Texas Instruments PLUS TI-92, PLUS TI-89 User Manual

TI-89 TI-92 Plus
Guidebook
for Advanced Mathematics Software Version 2.0
© 1999-2002 Texas Instruments
Important
In no event shall Texas Instruments be liable to anyone for special, collateral, incidental, or consequential damages in connection with or arising out of the purchase or use of these materials, and the sole and exclusive liability of Texas Instruments, regardless of the form of action, shall not exceed the purchase price of this calculator. Moreover, Texas Instruments shall not be liable for any claim of any kind whatsoever against the use of these materials by any other party.
US FCC Information Concerning Radio Frequency Interference
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference with radio communications. However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, you can try to correct the interference by one or more of the following measures:
¦ Reorient or relocate the receiving antenna. ¦ Increase the separation between the equipment and receiver. ¦ Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
¦ Consult the dealer or an experienced radio/television technician
for help.
Caution:
expressly approved by Texas Instruments may void your authority to operate the equipment.
Any changes or modifications to this equipment not
C

TI-89 Shortcut Keys

General
¥O 2a
List of Flash applications Toggle between last two chosen
applications or split screens
¥|, ¥« ¥¸ ¥C, ¥D
Lighten or darken contrast Calculate approximate answer Move cursor to top or bottom
(in editors)
¤ C, ¤ D ¤ A, ¤ B 2C, 2D
Scroll tall objects in history Highlight left or right from cursor Page up or page down
(in editors)
2A, 2B
On-screen Keyboard Map (
Move cursor far left or far right
¥^
)
Press N to exit the map.
The keyboard map displays shortcuts that are not marked on the keyboard. As shown below, press ¥ and then the applicable key.
¥Á ¥c
ƒ
Access Greek letters (see next column)
¥d ¥b
¥e ¥Í ¥
1 – ¥9
¥ p ¥^ ¥ § ¥´
(comment)
¦
Copy graph coordinates to
sysdata
(factorial)
!
FORMATS
Display Run programs
kbdprgm9()
through
&
(append)
dialog box
kbdprgm1()
On-screen keyboard map
@
Turn off unit so that it returns to current application the next time you turn it on
¥µ ¥¶ ¥·
(zero)
Copy graph coordinates to Home screen history
Alpha Rules
j ¤
2™
¤j j
Type one lowercase letter Type one uppercase letter Lowercase alpha lock Uppercase alpha lock Exit alpha lock
3D Graphing
B
, D, A,
«, |
X, Y, Z
µ Í p
Animate graph Change animation speed View along axis Return to original view Change graph format style Expanded/normal view
Greek Letters
¥c
To access the Greek character set
¥cj
+ letter To access lowercase Greek
letters. Example:
[W]
¥cj
¥c¤
+ letter To access uppercase Greek
displays
ω
letters. Example:
¥c¤
[W]
displays
If you press a key combination that does not access a Greek letter, you get the normal letter for that key.
ψξ
ζτ
XYZT
β
α
ABCDE
Γ
γ
φ
FGH I J
λ
KLMNO
Π π
PQRSU
Ω ω
VW
ε
δ
µ
Σ
ρ
σ

TI-92 Plus Shortcut Keys

General
¥ O
List of Flash applications
2a Toggle between last two chosen
applications or split screens
¥
¥ ¥
D
F H
Copy graph coordinates to
sysdata
Display
FORMATS
dialog box
Copy graph coordinates to Home screen history
N
¥
O
¥
S
¥ ¥ |, ¥ « ¥ ¸ ¥ ´
Create new variable Open existing variable Save copy as Lighten or darken contrast Calculate approximate answer Turn off unit so that it returns
to current application the next time you turn it on
1 – ¥ 9
¥
On-screen Keyboard Map (
Run programs through
kbdprgm9()
kbdprgm1()
¥ ”
)
Press N to exit the map.
See the table below for shortcuts that are not marked on the
TI-92 Plus
keyboard. See the next column for accent marks and Greek letters.
2 2 2 2 2 2 ¥ Á ¥ µ ¥ ¶
Q W R T H X
(zero)
? ! (factorial)
@
# (indirection)
(append)
&
¦ (comment)
ƒ
Editing
¥ C ¥ D
A
2
B
2
‚ C, ‚ D 2 C, 2 D
X
¥
C
¥
V
¥
Move cursor to top Move cursor to bottom Move cursor to far left Move cursor to far right Scroll tall objects in history Page up and page down Cut Copy Paste
3D Graphing
C, D, A, B «, |
X, Y, Z
(zero)
µ
F
p
Animate graph Change animation speed View along axis Return to original view Change graph format style Expanded/normal view
Accent Marks
2 2 2 2 2 2
A C E N O U
+ letter + letter + lette + letter
+ letter
+ letter
à, è, ì, ò, ù, À, È, Ì, Ò, Ù ç, Ç
r á, é, í, ó, ú, ý, Á, É, Í, Ó, Ú, Ý
ã, ñ, õ, Ã, Ñ, Õ â, ê, î, ô, û, Â, Ê, Î, Ô, Û ä, ë, ï, ö, ü, ÿ, Ä, Ë, Ï, Ö, Ü
Greek Letters
2
G
To access the Greek character set
G + letter
2
G ¤ + letter
2
To access lowercase Greek letters. Example: displays
ω
2
W
G
To access uppercase Greek letters. Example: displays
2
G ¤ W
If you press a key combination that does not access a Greek letter, you get the normal letter for that key.
ε
ω
ω
Q W E R T Y U I O P
ε
Q W E R T Y U I O P
Σ
Σ
α
A S D F G H J K L
δ
σ
σ
α
δ
A S D F G H J K L
ρ
ρ
φγ
φγ
ψ
τ
ψ
τ
Γ
Γ
Π
Π
π
π
λ
λ
ξζ
ξζ
Z X C V B N M
Z X C V B N M
µ
β
β
µ
q
q

Table of Contents

Chapter 1: Getting Started

Chapter 2: Operating the Calculator

This guidebook describes how to use the TI table of contents can help you locate "getting started" information as well as detailed information about the
TI-89 / TI-92 Plus features. Appendix A provides one convenient
location to find details about every TI and instruction.
Flash Applications...................................................................................... x
Keystroke Differences.............................................................................xii
What’s New?............................................................................................. xiv
Getting the TI.89 Ready to Use ................................................................ 2
Getting the TI.92 Plus Ready to Use........................................................ 3
Setting the Contrast and Selecting a Language...................................... 4
Performing Computations......................................................................... 8
Graphing a Function ................................................................................ 11
Turning the TI.89 / TI.92 Plus On and Off ............................................ 14
Setting the Display Contrast................................................................... 15
The TI.89 Keyboard ................................................................................. 16
The TI.92 Plus Keyboard......................................................................... 17
Modifier Keys............................................................................................ 18
Entering Alphabetic Characters............................................................. 21
Home Screen............................................................................................. 23
Entering Numbers .................................................................................... 25
Entering Expressions and Instructions................................................. 26
Formats of Displayed Results................................................................. 29
Editing an Expression in the Entry Line ............................................... 32
Menus......................................................................................................... 34
Using the Custom Menu .......................................................................... 37
Selecting an Application.......................................................................... 38
Setting Modes ........................................................................................... 40
Using the Clean Up Menu to Start a New Problem.............................. 43
Using the Catalog Dialog Box................................................................. 44
Storing and Recalling Variable Values................................................... 47
Reusing a Previous Entry or the Last Answer...................................... 49
Auto-Pasting an Entry or Answer from the History Area................... 52
Status Line Indicators in the Display..................................................... 53
Finding the Software Version and ID Number..................................... 55
89 / TI-92 Plus. The
-
89 / TI-92 Plus function
-
iii

Chapter 3: Symbolic Manipulation

Preview of Symbolic Manipulation........................................................ 58
Using Undefined or Defined Variables.................................................. 59
Using Exact, Approximate, and Auto Modes ....................................... 61
Automatic Simplification......................................................................... 64
Delayed Simplification for Certain Built-In Functions........................ 66
Substituting Values and Setting Constraints ........................................ 67
Overview of the Algebra Menu............................................................... 70
Common Algebraic Operations.............................................................. 72
Overview of the Calc Menu..................................................................... 75
Common Calculus Operations................................................................ 76
User-Defined Functions and Symbolic Manipulation ......................... 77
If You Get an Out-of-Memory Error....................................................... 79
Special Constants Used in Symbolic Manipulation ............................. 80

Chapter 4: Constants and Measurement Units

Chapter 5: Additional Home Screen Topics

Chapter 6: Basic Function Graphing

Chapter 7: Parametric Graphing

Preview of Constants and Measurement Units.................................... 82
Entering Constants or Units ................................................................... 83
Converting from One Unit to Another................................................... 85
Setting the Default Units for Displayed Results .................................. 87
Creating Your Own User-Defined Units................................................ 88
List of Pre-Defined Constants and Units............................................... 89
Saving the Home Screen Entries as a Text Editor Script ................... 94
Cutting, Copying, and Pasting Information .......................................... 95
Creating and Evaluating User-Defined Functions ............................... 97
Using Folders to Store Independent Sets of Variables ..................... 100
If an Entry or Answer Is “Too Big” ...................................................... 103
Preview of Basic Function Graphing................................................... 106
Overview of Steps in Graphing Functions.......................................... 107
Setting the Graph Mode......................................................................... 108
Defining Functions for Graphing ......................................................... 109
Selecting Functions to Graph ............................................................... 111
Setting the Display Style for a Function.............................................. 112
Defining the Viewing Window .............................................................. 113
Changing the Graph Format ................................................................. 114
Graphing the Selected Functions......................................................... 115
Displaying Coordinates with the Free-Moving Cursor...................... 116
Tracing a Function ................................................................................. 117
Using Zooms to Explore a Graph......................................................... 119
Using Math Tools to Analyze Functions ............................................. 122
Preview of Parametric Graphing.......................................................... 128
Overview of Steps in Graphing Parametric Equations ..................... 129
Differences in Parametric and Function Graphing ........................... 130
iv

Chapter 8: Polar Graphing

Preview of Polar Graphing.................................................................... 134
Overview of Steps in Graphing Polar Equations................................ 135
Differences in Polar and Function Graphing...................................... 136

Chapter 9: Sequence Graphing

Chapter 10: 3D Graphing

Chapter 11: Differential Equation Graphing

Preview of Sequence Graphing ............................................................ 140
Overview of Steps in Graphing Sequences......................................... 141
Differences in Sequence and Function Graphing .............................. 142
Setting Axes for Time, Web, or Custom Plots .................................... 146
Using Web Plots...................................................................................... 147
Using Custom Plots................................................................................ 150
Using a Sequence to Generate a Table................................................ 151
Preview of 3D Graphing ........................................................................ 154
Overview of Steps in Graphing 3D Equations.................................... 156
Differences in 3D and Function Graphing.......................................... 157
Moving the Cursor in 3D ....................................................................... 160
Rotating and/or Elevating the Viewing Angle..................................... 162
Animating a 3D Graph Interactively .................................................... 164
Changing the Axes and Style Formats................................................. 165
Contour Plots.......................................................................................... 167
Example: Contours of a Complex Modulus Surface ......................... 170
Implicit Plots........................................................................................... 171
Example: Implicit Plot of a More Complicated Equation................. 173
Preview of Differential Equation Graphing ........................................ 176
Overview of Steps in Graphing Differential Equations..................... 178
Differences in Diff Equations and Function Graphing...................... 179
Setting the Initial Conditions................................................................ 184
Defining a System for Higher-Order Equations ................................. 186
Example of a 2nd-Order Equation ....................................................... 187
Example of a 3rd-Order Equation........................................................ 189
Setting Axes for Time or Custom Plots............................................... 190
Example of Time and Custom Axes .................................................... 191
Example Comparison of RK and Euler ............................................... 193
Example of the deSolve( ) Function.................................................... 196
Troubleshooting with the Fields Graph Format ................................ 197
v

Chapter 12: Additional Graphing Topics

Preview of Additional Graphing Topics.............................................. 202
Collecting Data Points from a Graph................................................... 203
Graphing a Function Defined on the Home Screen........................... 204
Graphing a Piecewise Defined Function............................................. 206
Graphing a Family of Curves................................................................ 208
Using the Two-Graph Mode.................................................................. 209
Drawing a Function or Inverse on a Graph ........................................ 212
Drawing a Line, Circle, or Text Label on a Graph ............................. 213
Saving and Opening a Picture of a Graph ........................................... 217
Animating a Series of Graph Pictures ................................................. 219
Saving and Opening a Graph Database ............................................... 220

Chapter 13: Tables

Chapter 14: Split Screens

Chapter 15: Data/Matrix Editor

Chapter 16: Statistics and Data Plots

Preview of Tables................................................................................... 222
Overview of Steps in Generating a Table............................................ 223
Setting Up the Table Parameters ......................................................... 224
Displaying an Automatic Table ............................................................ 226
Building a Manual (Ask) Table............................................................. 229
Preview of Split Screens........................................................................ 232
Setting and Exiting the Split Screen Mode ......................................... 233
Selecting the Active Application .......................................................... 235
Preview of the Data/Matrix Editor....................................................... 238
Overview of List, Data, and Matrix Variables..................................... 239
Starting a Data/Matrix Editor Session................................................. 241
Entering and Viewing Cell Values........................................................ 243
Inserting and Deleting a Row, Column, or Cell.................................. 246
Defining a Column Header with an Expression................................. 248
Using Shift and CumSum Functions in a Column Header................ 250
Sorting Columns..................................................................................... 251
Saving a Copy of a List, Data, or Matrix Variable .............................. 252
Preview of Statistics and Data Plots.................................................... 254
Overview of Steps in Statistical Analysis............................................ 258
Performing a Statistical Calculation.................................................... 259
Statistical Calculation Types ................................................................ 261
Statistical Variables................................................................................ 263
Defining a Statistical Plot...................................................................... 264
Statistical Plot Types ............................................................................. 266
Using the Y= Editor with Stat Plots..................................................... 268
Graphing and Tracing a Defined Stat Plot .......................................... 269
Using Frequencies and Categories ...................................................... 270
If You Have a CBL 2/CBL or CBR......................................................... 272
vi

Chapter 17: Programming

Preview of Programming....................................................................... 276
Running an Existing Program............................................................... 278
Starting a Program Editor Session....................................................... 280
Overview of Entering a Program.......................................................... 282
Overview of Entering a Function......................................................... 285
Calling One Program from Another..................................................... 287
Using Variables in a Program ............................................................... 288
Using Local Variables in Functions or Programs.................................. 290
String Operations ................................................................................... 292
Conditional Tests ................................................................................... 294
Using If, Lbl, and Goto to Control Program Flow.............................. 295
Using Loops to Repeat a Group of Commands.................................. 297
Configuring the TI-89 / TI-92 Plus........................................................ 300
Getting Input from the User and Displaying Output ......................... 301
Creating a Custom Menu....................................................................... 303
Creating a Table or Graph..................................................................... 305
Drawing on the Graph Screen .............................................................. 307
Accessing Another TI.89 / TI.92 Plus, a CBL 2/CBL, or a
CBR..................................................................................................... 309
Debugging Programs and Handling Errors......................................... 310
Example: Using Alternative Approaches ............................................ 311
Assembly-Language Programs ............................................................. 313

Chapter 18: Text Editor

Chapter 19: Numeric Solver

Chapter 20: Number Bases

Preview of Text Operations.................................................................. 316
Starting a Text Editor Session.............................................................. 317
Entering and Editing Text..................................................................... 319
Entering Special Characters.................................................................. 324
Entering and Executing a Command Script ....................................... 328
Creating a Lab Report............................................................................ 330
Preview of the Numeric Solver ............................................................ 334
Displaying the Solver and Entering an Equation ............................... 335
Defining the Known Variables.............................................................. 337
Solving for the Unknown Variable....................................................... 339
Graphing the Solution............................................................................ 340
Preview of Number Bases..................................................................... 344
Entering and Converting Number Bases............................................. 345
Performing Math Operations with Hex or Bin Numbers .................. 346
Comparing or Manipulating Bits .......................................................... 347
vii

Chapter 21: Memory and Variable Management

Preview of Memory and Variable Management ................................. 350
Checking and Resetting Memory ......................................................... 353
Displaying the VAR-LINK Screen......................................................... 355
Manipulating Variables and Folders with VAR-LINK ........................ 357
Pasting a Variable Name to an Application ........................................ 359
Archiving and Unarchiving a Variable................................................. 360
If a Garbage Collection Message Is Displayed ................................... 362
Memory Error When Accessing an Archived Variable...................... 364

Chapter 22: Linking and Upgrading

Chapter 23: Activities

Appendix A: Functions and Instructions

Linking Two Units.................................................................................. 366
Transmitting Variables, Flash Applications, and Folders................. 367
Transmitting Variables under Program Control................................. 371
Upgrading Product Software (Base Code) ......................................... 373
Collecting and Transmitting ID Lists................................................... 378
Compatibility between a TI.89, TI.92 Plus, and TI.92 ...................... 380
Analyzing the Pole-Corner Problem .................................................... 384
Deriving the Quadratic Formula .......................................................... 386
Exploring a Matrix ................................................................................. 388
Exploring cos(x) = sin(x)...................................................................... 389
Finding Minimum Surface Area of a Parallelepiped.......................... 390
Running a Tutorial Script Using the Text Editor ............................... 392
Decomposing a Rational Function....................................................... 394
Studying Statistics: Filtering Data by Categories .............................. 396
CBL 2/CBL Program for the TI-89 / TI-92 Plus................................... 399
Studying the Flight of a Hit Baseball ................................................... 400
Visualizing Complex Zeros of a Cubic Polynomial............................. 402
Solving a Standard Annuity Problem................................................... 404
Computing the Time-Value-of-Money.................................................. 405
Finding Rational, Real, and Complex Factors.................................... 406
Simulation of Sampling without Replacement................................... 407
Quick-Find Locator ................................................................................ 410
Alphabetical Listing of Operations ...................................................... 414
viii

Appendix B: Reference Information

TI-89 / TI-92 Plus Error Messages ....................................................... 542
Modes....................................................................................................... 550
TI-89 / TI-92 Plus Character Codes ..................................................... 555
TI.89 Key Codes ..................................................................................... 556
TI.92 Plus Key Codes............................................................................. 559
Entering Complex Numbers ................................................................. 563
Accuracy Information............................................................................ 566
System Variables and Reserved Names .............................................. 567
EOS (Equation Operating System) Hierarchy.................................... 568
Regression Formulas ............................................................................. 570
Contour Levels and Implicit Plot Algorithm....................................... 572
Runge-Kutta Method .............................................................................. 573

Appendix C: Service and Warranty Information

Appendix D: Programmer’s Guide

Battery Information ............................................................................... 576
In Case of Difficulty ............................................................................... 579
Support and Service Information......................................................... 580
Warranty Information............................................................................ 581
setMode( ) and getMode( ) ................................................................... 584
setGraph( ) .............................................................................................. 587
setTable( ) ............................................................................................... 589
Index ........................................................................................................ 591
TI-89 Shortcut Keys TI-92 Plus Shortcut Keys
ix

Flash Applications

Applications
Hardware/Software
Requirements

Hardware Setup for the Computer

Installing a Flash Application from the CD-ROM

Note: For further
information about transmitting applications to and from your computer using TI Connect, refer to the TI Connect online help.
Flash functionality enables the ability to download different applications to a CD-ROM, the TI web site, or from another calculator.
Before downloading new applications to a read and accept the license agreement on the Applications CD-ROM.
Before installing Flash applications, you will need:
A computer with a CD-ROM drive and a serial port.
TI™ Connect
cable. If you need the
TI-GRAPH LINK
To set up:
1. Insert the small end of the
the bottom of the
2. Connect the other end to the computer’s serial port using a
25-to-9 pin adapter if necessary.
To install an application:
1. Insert the
computer’s CD-ROM drive.
2. From the computer, start the
3. From the
Certificates
4. Locate the Flash application on the CD-ROM and double-click.
The Flash application is copied to the calculator.
TI-89 / TI-92 Plus
TI-GRAPH LINK™
or
cable, check the TI web site at
TI-89
TI-89 / TI-92 Plus
Link
menu, click
.
calculator from the enclosed
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
TI Connect/ TI-GRAPH LINK
or the top of the
software and a
TI-GRAPH LINK
TI-92 Plus
Applications CD-ROM into the
TI-GRAPH LINK
Send Flash Software 8 Applications and
TI-GRAPH LINK
software or a
education.ti.com
cable into the port at
.
software.
, please
.

Running a Flash Application

x
To run an application:
1. On the
2. Use the cursor keys CD to highlight the application and press
TI-89 / TI-92 Plus

APPLICATIONS

¸.
menu.
, press ¥ O to display the
FLASH

Transferring a Flash Application from another TI-89 / TI-92 Plus

Note: This guidebook uses
screen shots.
TI-89
Do not attempt to transfer an application if a low-battery message appears on either the receiving or sending calculator.
1. Connect the calculators with the calculator-to-calculator cable
that came with the
TI-89 / TI-92 Plus
.
2. On the sending calculator:
a. Press 2
°
b. Press:
TI-89: TI-92 Plus:
2
c. Highlight the Flash application and press (a Ÿ is displayed
to the left of the selected item)
3. On the receiving calculator:
a. Press 2
°
b. Press
c. Select:
2:Receive
d. Press ¸
4. On the sending calculator:
a. Press
b. Select:
1:Send to TI-89/92 Plus
c. Press ¸

Backing up a Flash Application

Note: For further
information about transmitting applications to and from your computer using TI Connect, refer to the TI Connect online help.

Deleting a Flash Application

Note: To select all Flash applications, use the menu.
All
To back up an application to the computer:
1. On the calculator, press:
TI-89:
"
TI-92 Plus:
2. From the computer, start the
3. From the
¹ "
Link
menu, click
TI-GRAPH LINK
Receive Flash Software
software
4. Select one or more Flash applications and click add
5. Click ok
6. Save the application to the computer and record this information
for future reference.
To delete a Flash application from the calculator:
1. Press 2
°
to display the
VAR-LINK
screen
2. Press:
TI-89:
TI-92 Plus:
2
3. Highlight the Flash application and press (a Ÿis displayed to
the left of the selected item)
4. Press ƒ and choose
1:Delete
— or —
Press 0 (a confirmation message appears)
5. Press ¸ to confirm the deletion.
xi

Keystroke Differences

There are certain differences in keystrokes using the
TI-89 / TI-92 Plus
for various operations. The
following table shows the keystrokes for major commands for the two calculators.
FUNCTION LETTERS
One lowercase letter (a-s, u, v, w) One lowercase letter (t, x, y, z) Several lowercase letters End several lowercase letters Several uppercase letters End several uppercase letters
FUNCTION KEYS
F6 F7 F8
NAVIGATION
Scroll tall objects up or down in history Move cursor far left or far right on entry line Diagonal movement
j
T, X, Y, Z T, X, Y, Z
2 ™
j
¤ ™
j
2 ˆ
2 ‰
2 Š
¤ C, ¤ D
2 A, 2 B2
C C D D
FUNCTIONS
Display Home screen Cut Copy Paste Catalog Display Units dialog box Sin Cos Tan LN
õ¥
e EE
"
¥ 5
¥ 6
¥ 7
½
2 9
2 W
2 X
2 Y
2 x
^
³
TI-89
A-S, U-W A-S, U-W
A
and
B
and
A
and
B
and
s
TI-92 Plus
2 ¢ 2 ¢.
ˆ
Š
‚ C, ‚ D
A, 2 B
E F G H
¥ "
X
¥
C
¥
V
¥ 2 ½
9
¥
W
X
Y
x 2 s 2 ^
xii
FUNCTION SYMBOLS
ú
(Conversion triangle)
_ (Underscore) θ (Theta) | (“With”) ' (Prime)
° (Degree) (Angle) Σ (Sigma)
xê (Reciprocal) Space
HIDDEN SHORTCUTS
Place data in sysdata variable Greek characters Keyboard map Place data in Home screen history Grave (à, è, ì, ò, ù) Cedilla (ç) Acute (á, é, í, ó, ú, ý) Tilde (ã, ñ, õ) Caret (â, ê, î, ô, û) Umlaut (ä, ë, ï, ö, ü, ÿ) ? (Question mark) β (Beta) # (Indirection) & (Append) @ (Arbitrary) (Not equal to symbol) ! (Factorial) Comment (Circle-C) New Open Save copy as Format dialog box
³
TI-89
2 
¥ 
¥ Ï
Í
2 È
2 v
2 ’
½
Σ ( 2 >
½
^-1 2 V
j
¥ b
¥ c j
or ¥ c
¥ ^
¥ ·
2 ¿
2 ¿
2 ¿
2 ¿
2 ¿
2 ¿
2 ¿
2 ¿
2 ¿
¥ p
5 5 6 5 5 6 5 5 3 5 6 3
(times) 2
¥ §
¥ Á
¥ e
¥ d
¦
ƒ
3
ƒ
1
ƒ
2
¥ Í
¤
TI-92 Plus
2
2
Ï 2 Í
È
2
v
2
2
Space bar
D
¥
G
or ¥
¥ ¥
H
¥
A a, e, i, o, u
2
C c
2
E a, e, i, o, u, y
2
N a, n, o
2
O a, e, i, o, u
2
U a, e, i, o, u, y
2
Q
2
S
2
T
2
H R
2
V
2
W
2
X
2
N
¥
O
¥
S
¥
F
¥
G
¤
¦
xiii
What’s New?

Introducing Advanced Mathematics Software Version 2.0

Language Localization

TI developed the Advanced Mathematics Software Version 2.0 to enable downloadable calculator software applications for the
Advanced Mathematics Software Version 2.0 is an infrastructure enhancement of the current Advanced Mathematics Software Version 1.xx. It has all the features of Version 1.xx. The improved infrastructure enables multiple downloadable calculator software applications, language localization. This enhancement also provides your new over 702-KB Flash memory between user data archive and calculator software applications.
All previous
2.0. However, on some data archive can only occupy a maximum of 384-KB of the over 702­KB Flash memory shared with calculator software applications.
You can download Advanced Mathematics Software Version
2.0 to your computer from the TI web site at then transfer it to your TI
TI™ Connect
cable. The Advanced Mathematics Software is free from the TI web site at
The other languages. These free applications translate prompts, error messages, and most functions into one of several languages.
TI-89 / TI-92 Plus
TI-89
TI GRAPH LINK™
or
education.ti.com
TI-89 / TI-92 Plus
and
TI-89
and
can be localized into
TI-92 Plus
with maximum reapportionment of the
TI-92 Plus Modules
and all
TI-89
TI-92 Plus Module
89 / TI-92 Plus using the
-
software and a
.
For details, refer to:
Chapter 21 and 22
.
can be upgraded to Version
units, the user
education.ti.com
TI-GRAPH LINK
For details, refer to:
Chapter 1
,

Improved User Interface

xiv
The improved user interface allows folder collapse/expand and expands the user-defined functions.
CATALOG
menu to include application functions and

Upgradability with Flash ROM

The
TI-89 / TI-92 Plus
which lets you upgrade future software versions without buying a new calculator.
uses Flash technology,
For details, refer to:
Chapter 22
As new functionality becomes available, you can electronically upgrade your
TI-89 / TI-92 Plus
. Future software versions include maintenance upgrades that will be released free of charge, as well as new applications and major future upgrades that will be available for purchase from the TI web site.
To download upgrades from the TI web site, you must have an Internet-connected computer, software, and a
TI-GRAPH LINK
TI™ Connect or TI-GRAPH LINK™
cable. You can also transfer the product software (operating system) and Flash applications from one
TI-89 / TI-92 Plus
to another using a unit-to-unit cable, provided
that the receiving calculator is also licensed to run that software.

Custom Menu

New to the
TI-92 Plus
is the custom menu feature that lets you create your own toolbar menu. A custom menu can contain any available function, instruction, or set of characters. The
TI-92 Plus
has a default
custom menu that you can modify or redefine.
xv

Chapter 1: Getting Started

Getting the TI.89 Ready to Use ................................................................ 2
Getting the TI.92 Plus Ready to Use........................................................ 3
Setting the Contrast and Selecting a Language...................................... 4
Performing Computations......................................................................... 8
1
Graphing a Function ................................................................................ 11
This chapter helps you to get started using the quickly. This chapter takes you through several examples to introduce you to some of the principal operating and graphing functions of the
After setting up your examples, please read Chapter 2: Operating the Calculator. You then will be prepared to advance to the detailed information provided in the remaining chapters in this guidebook.
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
.
and completing these
TI-89 / TI-92 Plus
Chapter 1: Getting Started 1

Getting the TI-89 Ready to Use

-
The TI
89 comes with four AAA batteries. This chapter
describes how to install these batteries. It also describes how to turn the unit on for the first time, set the display contrast, select a language, and view the Home screen for both the
TI-89 and the TI-92 Plus.

Installing the AAA Batteries

Important: When replacing
batteries in the future, ensure that the turned off by pressing
.
TI-89
is
To install the four AAA batteries:
1. Place the
face down on a soft cloth to prevent scratching
TI-89
the display face.
2. On the back of the calculator, depress the battery cover latch. Lift
and remove the battery cover.
3. Remove the batteries from the package and install them in the
battery compartment. Arrange the batteries according to the polarity (+ and N) diagram in the battery compartment.
4. Replace the battery cover by inserting the two prongs into the
two slots at the bottom of the battery compartment, and then push the cover until the latch snaps closed.
To replace the batteries without losing any information stored in memory, follow the directions in Appendix C.
Lithium battery
AAA batteries
2 Chapter 1: Getting Started

Getting the TI-92 Plus Ready to Use

-
The TI
92 Plus comes with four AA batteries. This chapter
describes how to install these batteries. It also describes how to turn the unit on for the first time, set the display contrast, select a language, and view the Home screen for both the
TI-92 Plus and the TI-89.

Installing the AA Batteries

Important: When replacing
batteries in the future, ensure that the turned off by pressing
2 ®
TI-92 Plus
.
To install the four AA alkaline batteries:
1. Holding the
TI-92 Plus
unit upright, slide the latch on the top of the unit to the left unlocked position; slide the rear cover down about one-eighth inch and remove it from the main unit.
Slide to open.
is
2. Place the
TI-92 Plus
face down on a soft cloth to prevent
scratching the display face.
3. Install the four AA batteries. Be sure to position the batteries according to the diagram inside the unit. The positive (+) terminal of each battery should point toward the top of the unit.
AA batteries
Lithium battery
top
I/O
back
4. Replace the rear cover and slide the latch on the top of the unit to the right locked position to lock the cover back in place.
Chapter 1: Getting Started 3

Setting the Contrast and Selecting a Language

Turning the Unit on and Adjusting the Display Contrast

Languages on the TI-89 / TI-92 Plus

Important Information About the Language Process

Note: English cannot be
deleted and remains available in the product software (base code).
After you install the batteries in your possible that the display contrast may be too dark or too dim to see anything.
To adjust the display to your satisfaction, hold down ¥(diamond symbol inside a green border) and momentarily press |(minus key) to lighten the display. Hold down ¥and momentarily press «(plus key) to darken the display.
You will see a screen that lists several languages. The list of languages on your calculator may vary from this example.
Languages other than English are available as Flash applications. English is part of the product software (base code). You may keep as many or as few alternate languages on your calculator as you want (subject to memory limitation) and switch between them easily. During the process, you will be given an opportunity to choose additional languages to keep or delete. You may also add or delete language applications through the
The
TI-89 / TI-92 Plus
Localizing means that all menu names, dialog boxes, error messages, etc., will display in the language of your choice.
The
TI-89 / TI-92 Plus
time; however, you can keep additional languages on the unit and switch the language at any time.
The initial localization of the
¦
Phase I -
the
TI-89 / TI-92 Plus
selected language.
¦
Phase II -
language you selected in Phase I.
¦
Phase III -
selected in Phase I. You can now select one or more language applications that you would like to keep on the calculator (in case you want to switch to another language later). You can always reload one or more language applications later, if necessary. The calculator will then automatically delete the unselected languages.
can be localized into one of several languages.
can be localized into only one language at a
Select the language in which you would like to localize
. Future online instructions will appear in the
Read the instructional message that appears in the
The
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
VAR-LINK
TI-89 / TI-92 Plus
is localized into the language you
screen.
, press ´. It is
occurs in three phases:
4 Chapter 1: Getting Started

Localizing the TI-89 / TI-92 Plus

1. Press the cursor keys (D or C) to move the pointer to the language in which you would like to set your
TI-89 / TI-92 Plus
. (The list of languages on your calculator may vary from this example.)
Note: Until you complete the localization process, the Select a Language dialog box will reappear when you turn the unit on.
2. Press
¸
to set the
TI-89 / TI-92 Plus
into the selected language. (Pressing N halts the localization process and displays the Home screen.)
3. Read the message that appears and then press
¸
.
The message displays in the language you previously selected.
4. Press the cursor keys (D or C) to move the pointer and then press ƒ to select each additional language that you would like to keep. — or — Press „ to select and keep
You cannot uncheck English or the language you selected in step 1.
Pressing ƒ toggles the Ÿ on and off.
5. Press
¸
to complete the localization process. Additional
of the language applications.
all
selected languages, if any, are retained in memory and unselected languages are deleted to free up Flash memory. (Pressing
N
halts the localization process and displays the Home screen.)
If additional language applications remain on your you can change the localization language via
Page 3
TI-89 / TI-92 Plus
(…) of the
,
Mode
dialog box. See “Setting Modes” in Chapter 2 for information on how
Mode
to use the Flash applications via the
dialog box. You can add or delete language and other
VAR-LINK
screen. See “Transmitting
Variables, Flash Applications, and Folders” in Chapter 22.
Language applications are available on the enclosed CD and from the Texas Instruments web site. For up-to-date information about Flash applications, including additional language applications, check the Texas Instruments web site at:
education.ti.com
Chapter 1: Getting Started 5

About the Home Screen

History Area
Lists entry/answer pairs you have entered. Pairs scroll up the screen as you make new entries.
After you select a language, a blank Home screen is displayed.
The Home screen lets you execute instructions, evaluate expressions, and view results.
The following example contains previously entered data and describes the main parts of the Home screen. Entry/answer pairs in the history area are displayed in “pretty print.” Pretty print displays expressions in the same form in which they are written on the board or in textbooks.
Toolbar
Lets you display menus for selecting operations applicable to the Home screen. To display a toolbar menu, press ƒ, „, etc.
Last Entry
Your last entry.
Entry Line
Where you enter expressions or instructions.
6 Chapter 1: Getting Started
Status Line
Shows the current state of the calculator.
Last Answer
Result of your last entry. Note that results are not displayed on the entry line.
The following example shows an answer that is not on the same line as the expression. Note that the answer is longer than the screen width. An arrow (8) indicates the answer is continued. The entry line contains ellipsis (…). Ellipsis indicates the entry is longer than the screen width.
Last Entry
"Pretty print" is ON. Exponents, roots, fractions, etc., are displayed in the same form in which they are traditionally written.
Answer Continues
Highlight the answer and press B to scroll right and view the rest of it. Note that the answer is not on the same line as the expression.
Expression Continues
Press B to scroll right and view the rest of the entry. Press 2 A or 2 B to go to the beginning or end of the entry line.

Turning the TI-89 / TI-92 Plus Off

When you want to turn the
TI-89 / TI-92 Plus
off, press
(Note: ® is the second function of the ´ key.)
Chapter 1: Getting Started 7
.

Performing Computations

This section provides several examples for you to perform that demonstrate some of the computational features of the TI
-
89 / TI-92 Plus. The history area in each screen was
cleared by pressing ƒand selecting 8:Clear Home, before performing each example, to illustrate only the results of the example’s keystrokes.
Steps
³
TI.89
Keystrokes
TI.92 Plus
Keystrokes Display
Showing Computations
1. Compute result in symbolic and numeric format.
To clear the history area of previous
calculations, press
8:Clear Home.
sin(p/4)
and display the
ƒ
and select
2W2T e4d¸ ¥¸
W2T e4d¸ ¥¸
Finding the Factorial of Numbers
1. Compute the factorial of several numbers to see how the
TI-89 / TI-92 Plus
handles very
large integers.
To get the factorial operator (!), press
2I
, select
then select
1:!
.
7:Probability
, and
5
2I
¸
20
2I
¸
30
2I
¸
71
71
71
52W
202W
302W
¸
¸
¸
Expanding Complex Numbers
3
1. Compute
TI-89 / TI-92 Plus
(3+5i)
handles
to see how the
computations involving complex numbers.
Finding Prime Factors
1. Compute the factors of the
2634492
on the
.
and
rational number
You can enter “factor” on the entry
line by typing keyboard, or by pressing selecting
2. (
Optional
FACTOR
2:factor(
.
) Enter other numbers
on your own.
8 Chapter 1: Getting Started
c3«52) dZ3¸
2
2634492
¸
d
c3«52) dZ3¸
2
2634492
¸
d
Steps
Expanding Expressions
3
.
(xì5)
on the
.
and
1. Expand the expression
You can enter “expand” on the entry
line by typing keyboard, or by pressing selecting
2. (
Optional
EXPAND
3:expand(
) Enter other
expressions on your own.
Reducing Expressions
1. Reduce the expression
2
5)/(xì1)
(x
ì2xì
to its simplest
form.
You can enter “propFrac” on the entry
line by typing keyboard, or by pressing selecting
PROPFRAC
7:propFrac(.
on the
and
Factoring Polynomials
2
5)
1. Factor the polynomial
(x
ì
with respect to x.
You can enter “factor” on the entry
line by typing keyboard or by pressing selecting
FACTOR
2:factor(
on the
and
.
³
TI.89
Keystrokes
3
„ cX|5dZ d ¸
7
„ cXZ2|
2X
|5de cX|1dd ¸
2
XZ2|5
bXd ¸
TI.92 Plus
Keystrokes Display
3
3
cX|5dZ
3
d ¸
7
„ cXZ2|
2X
|5de cX|1dd ¸
2
XZ2|5
bXd ¸
Solving Equations
2
6=2
1. Solve the equation
x
ì2xì
with respect to x.
You can enter “solve(” on the entry
line by selecting Catalog menu, by typing the keyboard, or by pressing selecting
The status line area shows the
required syntax for the marked item in the Catalog menu.
1:solve(
“solve(”
.
from the
SOLVE(
and
XZ2|2X|6
Á2bXd ¸
on
1
1
XZ2|2X|6
Á2bXd ¸
Chapter 1: Getting Started 9
Steps
Í
Solving Equations with a Domain Constraint
2
6=2
1. Solve the equation
x
ì2xì
with respect to x where x is greater than zero.
The “with” (I) operator provides
domain constraint.
TI.89:
Í
TI.92 Plus:
2
Finding the Derivative of Functions
1. Find the derivative of
(xìy)3/(x+y)
This example illustrates using the
calculus differentiation function and how the function is displayed in “pretty print” in the history area.
2
with respect to x.
Finding the Integral of Functions
1. Find the integral of respect to
This example illustrates using the
calculus integration function.
x
xùsin(x)
with
.
³
TI.89
Keystrokes
1
XZ2|2X|6
Á2bXd
X
Í
0
2Ã ¸
2=cX|
Y
dZ3ecX«
YdZ2bX
d
¸
2<Xp 2WXdb
X
TI.92 Plus
Keystrokes Display
1
XZ2|2X|6
Á2bXd
X
2 Í
0
2Ã ¸
2=cX|
Y
dZ3ecX«
YdZ2bX
d
¸
2<Xp WXdb
X
10 Chapter 1: Getting Started

Graphing a Function

The example in this section demonstrates some of the graphing capabilities of the
TI-89 / TI-92 Plus. It illustrates how to graph a function using the Y= Editor. You will learn
how to enter a function, produce a graph of the function, trace a curve, find a minimum point, and transfer the minimum coordinates to the Home screen.
Explore the graphing capabilities of the TI
2
ì3|ì
10)/2
.
y=(|x
-
89 / TI-92 Plus by graphing the function
Steps
1. Display the Y= Editor.
2. Enter the function
(abs(x
2
ì3)ì
10)/2
.
3. Display the graph of the function.
Select
6:ZoomStd
moving the cursor to pressing
¸
.
by pressing 6 or by
6:ZoomStd
and
4. Turn on Trace.
The tracing cursor, and the x and y
coordinates are displayed.
³
TI.89
Keystrokes
¥#
c½ ¸
XZ2|3 10de2
¸
6
A
d|
TI.92 Plus
Keystrokes Display
¥#
c
A
¸
XZ2|3
d|
10de2
¸
6
entry line
“pretty print” display of the function in the entry line
tracing cursor
Open the
5.
3:Minimum
MATH
menu and select
.
‡DD¸
‡DD¸
Chapter 1: Getting Started 11
Steps
6. Set the lower bound.
Press B(right cursor) to move the
tracing cursor until the lower bound for x is just to the left of the minimum node before pressing second time.
¸
the
7. Set the upper bound.
Press B(right cursor) to move the
tracing cursor until the upper bound for x is just to the right of the minimum node.
³
TI.89
Keystrokes
B
B
...
¸
B
B
...
TI.92 Plus
Keystrokes Display
B
B
...
¸
B
B
...
8. Find the minimum point on the graph between the lower and upper bounds.
9. Transfer the result to the Home screen, and then display the Home screen.
Shortcuts for copying graph
coordinates to Home screen history:
¥·
TI.89: TI.92 Plus:
H
¥
¸
¥· "
¸
H
¥ ¥"
minimum coordinates
minimum point
12 Chapter 1: Getting Started

Chapter 2: Operating the Calculator

Turning the TI.89 / TI.92 Plus On and Off ............................................ 14
Setting the Display Contrast................................................................... 15
The TI.89 Keyboard ................................................................................. 16
The TI.92 Plus Keyboard......................................................................... 17
2
Modifier Keys............................................................................................ 18
Entering Alphabetic Characters............................................................. 21
Home Screen............................................................................................. 23
Entering Numbers .................................................................................... 25
Entering Expressions and Instructions................................................. 26
Formats of Displayed Results................................................................. 29
Editing an Expression in the Entry Line ............................................... 32
Menus......................................................................................................... 34
Using the Custom Menu .......................................................................... 37
Selecting an Application.......................................................................... 38
Setting Modes ........................................................................................... 40
Using the Clean Up Menu to Start a New Problem.............................. 43
Using the Catalog Dialog Box................................................................. 44
Storing and Recalling Variable Values................................................... 47
Reusing a Previous Entry or the Last Answer...................................... 49
Auto-Pasting an Entry or Answer from the History Area................... 52
Status Line Indicators in the Display..................................................... 53
Finding the Software Version and ID Number..................................... 55
This chapter gives a general overview of the describes its basic operations. By becoming familiar with the information in this chapter, you can use the solve problems more effectively.
The Home screen is the most commonly used application on the
TI-89 / TI-92 Plus
variety of mathematical operations.
. You can use the Home screen to perform a wide
Chapter 2: Operating the Calculator 13
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
and
to

Turning the TI-89 / TI-92 Plus On and Off

Turning the TI-89 / TI-92 Plus On

Turning the TI-89 / TI-92 Plus Off

Note: ®is the second
function of the
´
key.
You can turn the TI the ´and the APDé (Automatic Power Downé) feature lets the
TI-89 / TI-92 Plus turn itself off automatically.
Press ´.
¦ If you turned the unit off by pressing
returns to the Home screen.
¦ If you turned the unit off by pressing
itself off through APD, the application you used last.
You can use either of the following keys to turn off the
Press: Description
2
(press and then press ®)
¥®
¥
(press and then press ®)
89 / TI-92 Plus on and off manually by using
-
Settings and memory contents are retained by the Constant Memoryé feature. However:
¦ You cannot use
¦ When you turn the
Similar to
¦ You can use
¦ When you turn the
¥®
(or
displayed.
always displays the Home screen (regardless of the last application you used).
displayed.
will be exactly as you left it.
) keys. To prolong battery life,
¥®
or if the unit turned
TI-89 / TI-92 Plus
except:
¥®
returns to whichever
if an error message is
TI-89 / TI-92 Plus
if an error message is
TI-89 / TI-92 Plus
, the
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
on again, it
on again, it
.

APD (Automatic Power Down)

After several minutes without any activity, the itself off automatically. This feature is called APD.
When you press ´, the
¦ The display, cursor, and any error conditions are exactly as you
left them.
¦ All settings and memory contents are retained.
APD does not occur if a calculation or program is in progress, unless the program is paused.

Batteries

14 Chapter 2: Operating the Calculator
The battery. The back-up lithium battery. To replace the batteries in either calculator without losing any information stored in memory, follow the directions in Appendix C.
uses four AAA alkaline batteries and a back-up lithium
TI-89
TI-92 Plus
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
uses four AA alkaline batteries and also has a
will be exactly as you left it.
turns

Setting the Display Contrast

The brightness and contrast of the display depend on room lighting, battery freshness, viewing angle, and the adjustment of the display contrast. The contrast setting is retained in memory when the TI
-
89 / TI-92 Plus is turned off.

Adjusting the Display Contrast

When to Replace Batteries

Tip: The display may be
very dark after you change batteries. Use lighten the display.
¥|
to

Using the TI-92 Plus Cover as a Stand

You can adjust the display contrast to suit your viewing angle and lighting conditions.
To: Press and hold both:
¥
Decrease (lighten) the contrast Increase (darken) the contrast
contrast keys
TI-89
VAR-LINK O
CHAR U
TI-92 Plus
|
and
¥
«
and
contrast keys
VAR-LINK
CHAR
If you press and hold ¥|or ¥«too long, the display may go completely black or blank. To make finer adjustments, hold ¥and then tap |or «.
As the batteries get low, the display begins to dim (especially during calculations) and you must increase the contrast. If you have to increase the contrast frequently, replace the four alkaline batteries.
The status line along the bottom of the display also gives battery information.
Indicator in status line Description
Batteries are low.
Replace batteries as soon as possible.
When using the
TI-92 Plus
on a desk or table top, you can use the snap-on cover to prop up the unit at one of three angles. This may make it easier to view the display under various lighting conditions.
Note: Slide the tabs at the top-sides of the into the slots in the cover.
TI-92 Plus
Chapter 2: Operating the Calculator 15

The TI-89 Keyboard

A

Overview of Some Important Keys

through 2
ƒ
function keys let you
select toolbar menus.
Used with ¥, you can
also select applications
Š
(page 39).
Use this section to familiarize yourself with the various keys on
-
the TI
89 keyboard. Most keys can perform two or more
functions, depending on whether you first press a modifier key.
cancels a menu or
N
dialog box.
2, ¥, ¤
modify the action of
other keys (page 18).
"
X, Y, and Z are often
3
change
determine how numbers
and graphs are interpreted,
calculated, and displayed
, and
displays the Home screen, where you
perform most
calculations.
used in symbolic
calculations.
lets you view and
mode settings that
(page 40).

Moving the Cursor

j
¸
executes an instruction, selects a menu item, etc.
You can use
approximate numerical result.
, B, C, and D move
the cursor.
lets you select an
O
application (page 38).
erases the entry
M
line. Also used to delete an entry/answer pair in the history area.
½
from a list of functions and instructions (page 44).
Adjust the contrast by pressing ¥ | (lighten) or
(darken).
¥ «
valuates an expression,
e
¥ ¸
To move the cursor in a particular direction, press the appropriate cursor key (A, B, C, or D).
Some
¦
¦
¦
¦
applications also let you press:
TI-89
2 A
or 2 B to move to the beginning or end of a line.
2 C
or 2 D to move up or down one screen at a time.
¥ C
or ¥ D to move to the top or bottom of a page.
C
and A, C and B, D and A, or D and B to move diagonally.
(Press the indicated cursor keys simultaneously.)
lets you select
to display an
16 Chapter 2: Operating the Calculator

The TI-92 Plus Keyboard

j

Keyboard Areas

Function Keys
Access the toolbar menus displayed across the top of the screen.
Application Shortcut Keys
Used with the
¥
key to let you select commonly used applications.
HOME Y= WINDOW GRAPH TblSet TABLE
QWERTY Keyboard
Enters text characters
ust as you would on a
typewriter.
With the TI
-
92 Plus’s easy-to-hold shape and keyboard layout,
you can quickly access any area of the keyboard even when you are holding the unit with two hands.
The keyboard is divided into several areas of related keys.

Cursor Pad

Moves the display cursor in up to 8 directions, depending on the application.
TI-92 Plus
Calculator Keypad
Performs a variety of math and scientific operations.
Cursor Pad
To move the cursor, press the applicable edge of the cursor pad. This guidebook uses key symbols such as A and B to indicate which side of the cursor pad to press.
For example, press B to move the
C
cursor to the right.
The diagonal directions
Note:
(H, etc.) are used only for geometry
A
B
and graphing applications.
D
Chapter 2: Operating the Calculator 17

Modifier Keys

Modifier Keys

Note: For information about
and j, refer to
using
¤
“Entering Alphabetic Characters” on page 21.
Examples of
2
and ¥ Modifiers
Modifier Description
2
(second)
Accesses the second function of the next key you press. On the keyboard, these are printed in the same color as the 2 key.
¥
(diamond)
Activates keys that select certain applications (page 39), menu items, and other operations from the keyboard. On the keyboard, these are printed in the same color as the ¥ key.
¤
(shift)
Types an uppercase character for the next letter key you press. ¤is also used with Band Ato highlight characters in the entry line for editing purposes.
j
(TI-89 only)
Used to type alphabetic letters, including a space character. On the keyboard, these are printed in the same color as the j key.
(hand)
(TI-92 Plus only)
Used with the cursor pad to manipulate geometric objects. is also used for drawing on a graph.
The N key is one of several keys that can perform three operations, depending on whether you first press 2 or ¥.
The following
example shows using the 2 or ¥ modifier key
TI-89
with the N key.
accesses
accesses
2 K
QUIT
, which is the
same color as the
2
key.
QUIT PASTE
ESC
¥ 7
which is the same color as the ¥ key.
PASTE
,
The following key with the
accesses
2 
(convert). The
convert symbol is
the same color as
the 2 key.
18 Chapter 2: Operating the Calculator
N
TI-92 Plus
Y
alphabetic key.
example shows using the 2 or ¥ modifier
ú
primary key types
accesses the
key’s primary
function.
ú
TABLE
Y
Pressing the
the letter Y.
displays the
¥ '
Table screen. The word is the same color as the key.
¥
Some keys perform only one additional operation, which may require
k
either 2 or ¥, depending on the color in which the operation is printed on the keyboard and where it is positioned above the key.
CUT
2nd
When you press a modifier such as 2 or ¥, a
On the TI-89, ¥ accesses is the same color as the ¥ key.
2ND
5
CUT
, which
or 2 indicator appears in the status line at the bottom of the display. If you press a modifier by accident, press it again (or press N) to cancel its effect.

Other Important Keys You Need to Be Familiar With

Note: Some keystrokes
differ between the the Keystroke Differences table in the front of this guideboo for a complete list.
TI-92 Plus
. See the
TI-89
and
Key Description
¥ #
¥ $
¥ %
¥ &
¥ '
TI.89:
5
¥
6
¥
7
¥
TI.92 Plus:
X (cut)
¥
C (copy)
¥
V (paste)
¥
2 a
2 ¾
2 
TI.89:
¥
TI.92 Plus:
Displays the Y= Editor (Chapter 6).
Displays the Window Editor (Chapter 6).
Displays the Graph screen (Chapter 6).
Sets parameters for the Table screen (Chapter 13).
Displays the Table screen (Chapter 13).
These keys let you edit entered information by performing a cut, copy, or paste operation.
Switches the active side in a split screen (Chapter 14).
Toggles the custom menu on and off (page 37).
Converts measurement units (Chapter 4).
Designates a measurement unit (Chapter 4).
2
0
Deletes the character to the left of the cursor (backspaces).
2 /
Toggles between insert and overtype mode for entering information (page 33).
¥ 8
Deletes the character to the right of the cursor.
Chapter 2: Operating the Calculator 19
Important Keys (continued)
Key Description TI.89:
Í
TI.92 Plus:
Enters the “with” operator, which is used in symbolic calculations (Chapter 3).
2 Í
2 <
,
Performs integrations and derivatives (Chapter 3).
2 =
2 ’
Designates an angle in polar, cylindrical, and spherical coordinates.
2 I
2 ¯
2 °
2 £
TI.89:
2
TI.92 Plus:
Displays the
Displays the
Displays the and Flash applications (Chapter 21).
Recalls the contents of a variable (page 48).
Displays the
9
¥ À
2 ¿
Displays the letters, international accented characters, etc. (Chapter 18).
2 ±
,
2 ²
Recalls the previous entry and the last answer, respectively (page 49).
MATH
menu.
MEMORY VAR-LINK
UNITS
CHAR
screen (Chapter 21).
screen for managing variables
dialog box (Chapter 4).
menu, which lets you select Greek
20 Chapter 2: Operating the Calculator

Entering Alphabetic Characters

Alphabetic characters are used in expressions such as xñ+yñ, to enter variable names (page 47), and in the Text Editor (Chapter 18).

Entering a Letter Character on the TI-89

Typing Alphabetic Characters on the TI-89 / TI-92 Plus

Note: On the
not need to type x, y, z, or t. But you must use
-lock for X, Y, Z, or T.
ALPHA
Note: On the lock is always turned off when you change applications, such as going from the Text Editor to the Home screen.
TI-89
or alpha-lock
j
or uppercase
¤
TI-89
, you do
, alpha-
The letters x, y, z, and t are commonly used in algebraic expressions. So that you can type them quickly, these letters are primary keys on
keyboard.
the
TI-89
X Y Z T
Other letters are available as the j function of another key, similar to the 2 and ¥ modifiers described in the previous section. For example:
types
2 È
is the same color as
To: On the TI.89, press: On the TI.92 Plus, press:
Type a single lowercase alpha
, which
´
the 2 key.
j
and then the letter key (status line shows
´
A
=
)
[A] types an A,
j
which is the same color as the j key.
the letter key
character. Type a single
uppercase
¤
and then the letter key
(status line shows +)
¤
and then the letter key
(status line shows +) alpha character.
Type a space.
j 
(alpha function
spacebar
of the · key)
Turn on lowercase
2 ™
(status line shows
(no action needed)
)
alpha-lock. Turn on
uppercase
¤ ™
(status line shows
2 ¢
)
ALPHA-lock. Turn off alpha-
lock.
j
(turns off upper-
and lowercase lock)
2 ¢ (turns off
uppercase lock)
Chapter 2: Operating the Calculator 21
Typing Alphabetic Characters … (continued)
On the
¦
To type a period, comma, or other character that is the primary
, while either type of alpha-lock is on:
TI-89
function of a key, you must turn alpha-lock off.
¦
To type a second function character such as 2 [, you do not need to turn alpha-lock off. After you type the character, alpha­lock remains on.
Automatic Alpha­Lock in TI-89 Dialog Boxes
Note: To type a number,
press lock off. Press
2 ™
letters.
to turn alpha-
j
j
to resume typing
or

For Special Characters

There are certain times when you do not need to press j or
2 ™
to type alphabetic characters on the
TI-89
. Automatic alpha-lock is turned on whenever a dialog box is first displayed. The automatic alpha-lock feature applies to these dialog boxes:
Dialog box Alpha-lock
Catalog dialog box
All commands are listed in alphabetical order. Press a letter to go to the first command that begins with that letter. See page 44 for more information.
Units dialog box
In each unit category, type the first letter of a unit or constant. See Chapter 4 for more information.
Dialog boxes with entry fields
These include, but are not limited to:
New Folder
Rename
,
, and
Save Copy As
Create
. See page 35 for more information about dialog boxes.
Alpha-lock is
turned on in dialog boxes that require numeric-
not
only entries. The dialog boxes that accept only numeric entries are:
Resize Matrix, Zoom Factors
, and
Table Setup
.
Use the 2 ¿ menu to select from a variety of special characters. For more information, refer to “Entering Special Characters” in Chapter 18.
22 Chapter 2: Operating the Calculator

Home Screen

Displaying the Home Screen

Parts of the Home Screen

Pretty Print Display
Shows exponents, roots, fractions, etc., in traditional form. Refer to page 29.
Last Entry
Your last entry.
Entry Line
Where you enter expressions or instructions.
When you first turn on your TI
-
89 / TI-92 Plus, the Home screen
is displayed. The Home screen lets you execute instructions, evaluate expressions, and view results.
When you turn on the
®
2
, the display always shows the Home screen. (If the
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
turned itself off through APDé, the display shows the
after it has been turned off with
previous screen, which may or may not have been the Home screen.) To display the Home screen at any time:
¦
Press:
"
TI.89: TI.92 Plus:
¥"
— or —
¦
Press
2K
— or —
¦
Press:
TI.89: TI.92 Plus:
O
j
O
A A
The following example gives a brief description of the main parts of the Home screen.

History Area

Lists entry/answer pairs you have entered.
Toolbar
Press ƒ, „, etc., to display menus for selecting operations.
Last Answer
Result of your last entry. Note that results are not displayed on the entry line.
Status Line
Shows the current state of the TI-89 / TI-92 Plus.
History Area
The history area shows up to eight previous entry/answer pairs (depending on the complexity and height of the displayed expressions). When the display is filled, information scrolls off the top of the screen. You can use the history area to:
¦
Review previous entries and answers. You can use the cursor to view entries and answers that have scrolled off the screen.
¦
Recall or auto-paste a previous entry or answer onto the entry line so that you can re-use or edit it. Refer to pages 50 and 52.
Chapter 2: Operating the Calculator 23
V
V

Scrolling through the History Area

Note: For an example of
viewing a long answer, refer to page 28.
Normally, the cursor is in the entry line. However, you can move the cursor into the history area.
To: Do this:
iew entries or answers that have scrolled off the screen
1. From the entry line, press Cto highlight the last answer.
2. Continue using Cto move the cursor from answer to entry, up through the history area.
Go to the oldest or newest history pair
iew an entry or answer that is too long for one line (úis at end of line)
If the cursor is in the history area, press
¥ C
or ¥ D, respectively.
Move the cursor to the entry or answer. Use A and B to scroll left and right (or
2 A
and 2 B to go to the beginning
or end), respectively.
Return the cursor to the entry line
Press N, or press Duntil the cursor is back on the entry line.

History Information on the Status Line

Use the history indicator on the status line for information about the entry/answer pairs. For example:
If the cursor is on the entry line:
If the cursor is in the history area:
Total number of pairs that are currently saved.
Pair number of the highlighted entry or answer.
8/30
Maximum number of pairs that can be saved.
Total number of pairs that are currently saved.
By default, the last 30 entry/answer pairs are saved. If the history
30/30
area is full when you make a new entry (indicated by
), the new entry/answer pair is saved and the oldest pair is deleted. The history indicator does not change.

Modifying the History Area

To: Do this:
Change the number of pairs that can be saved
Press ƒand select
TI.89:
¥Í
9:Format
TI.92 Plus:
¥
, or press
F
. Then press B, use Cor Dto highlight the new number, and press
Clear the history area and delete all saved pairs
Delete a particular entry/answer pair
24 Chapter 2: Operating the Calculator
Press ƒand select enter
ClrHome
on the entry line.
Move the cursor to either the entry or answer. Press 0or
¸
twice.
8:Clear Home
M
.
, or

Entering Numbers

The keypad lets you enter positive and negative numbers for your calculations. You can also enter numbers in scientific notation.

Entering a Negative Number

Important: Use |for
subtraction and use
for negation.
·

Entering a Number in Scientific Notation

1. Press the negation key ·. (Do not use the subtraction key |.)
2. Type the number. To see how the
TI-89 / TI-92 Plus
evaluates a negation in relation to other functions, refer to the Equation Operating System (EOSé) hierarchy in Appendix B. For example, it is important to know that
ñ
x
functions such as Use cand dto include
are evaluated before negation.
Evaluated as ë(2ñ)
parentheses if you have any doubt about how a negation will be evaluated.
If you use |instead of ·(or vice versa), you may get an error message or you may get unexpected results. For example:
¦
9
7
=
63
ë
— but —
p|
9
7
displays an error message.
¦
|
6
2
4
=
— but —
6 ·2 = ë12
¦
·2 «
since it is interpreted as
4 = 2
6(ë2)
, implied multiplication.
— but —
4
subtracts 2 from the previous answer and then adds 4.
|2 «
1. Type the part of the number that precedes the exponent. This
value can be an expression.
2. Press:
^
TI.89: TI.92 Plus:
E
appears in the display.
2
^
3. Type the exponent as an integer with up to 3 digits. You can use a
negative exponent.
Entering a number in scientific notation does not cause the answers to be displayed in scientific or engineering notation.
The display format is determined by the mode settings (pages 29 through
31) and the magnitude of the number.
Represents 123.45 × 10
-2
Chapter 2: Operating the Calculator 25

Entering Expressions and Instructions

You perform a calculation by evaluating an expression. You initiate an action by executing the appropriate instruction. Expressions are calculated and results are displayed according to the mode settings described on page 29.

Definitions

Note: Appendix A describes
all of the
TI-89 / TI-92 Plus
built-in functions and instructions.
Note: This guidebook uses the word command as a generic reference to both functions and instructions.

Implied Multiplication

Expression Consists of numbers, variables, operators, functions,
and their arguments that evaluate to a single answer.
p
ñ
3
r
For example:
¦
Enter an expression in the same order that it
.
+
normally is written.
¦
In most places where you are required to enter a value, you can enter an expression.
Operator Performs an operation such as +, ì, ù, ^.
¦
Operators require an argument before and after the operator. For example:
4+5
and
5^2
.
Function Returns a value.
¦
Functions require one or more arguments (enclosed in parentheses) after the function. For example:
(5)
and
min
(5,8)
.
Instruction Initiates an action.
¦
Instructions cannot be used in expressions.
¦
The
TI-89 / TI-92 Plus
Some instructions do not require an argument. For example:
¦
Some require one or more arguments. For example:
ClrHome
Circle
recognizes implied multiplication, provided it
.
0,0,5
.
For instructions, do not put the arguments in parentheses.
does not conflict with a reserved notation.
If you enter: The TI.89 / TI.92 Plus interprets it as:
p
Valid
Invalid
26 Chapter 2: Operating the Calculator
2 4 sin(46) 4ùsin(46)
5(1+2) [1,2]a [a 2a] 2(a) 2ùa
xy a(2) a[1,2]
(1+2)5 5ù(1+2)
or
p
2
ù
(1+2)ù5
or
Single variable named Function call Matrix index to element
xy
a[1,2]

Parentheses

Expressions are evaluated according to the Equation Operating System (EOSé) hierarchy described in Appendix B. To change the order of evaluation or just to ensure that an expression is evaluated in the order you require, use parentheses.
Calculations inside a pair of parentheses are completed first. For example, in answer by
4(1+2)
, EOS first evaluates
4
.
(1+2)
and then multiplies the

Entering an Expression

Example
Note: You can also select
by using
log
TI.89:
½
TI.92 Plus:
(page 44).
2 ½
Type the expression, and then press
¸
to evaluate it. To enter a
function or instruction name on the entry line, you can:
Press its key, if available. For example, press
¦
TI.92 Plus:
W.
TI.89:
2W
— or — Select it from a menu, if available. For example, select
¦
the
Number
submenu of the
MATH
menu.
2:abs
— or — Type the name letter-by-letter from the keyboard. (On the
¦
use j and 2 ™ to type letters.) You can use any mixture of uppercase or lowercase letters. For example, type
Type the function name in this
Calculate
On the TI.89: On the TI.92 Plus: Display
3.76
c· «2]
5
« 2™ c45d
¸¸
3.76 ÷ (ë7.9 + ‡5) + 2 log 45
e
7.9
dd
2
LOG
j
3.76
e
7.9
c· «2]
5
dd
2
«
LOG
c45d
example.
.
3.76/(ë7.9+‡(
inserts ‡( because its
2 ]
argument must be in parentheses.
3.76/(ë7.9+(5))
Use d once to close ‡(5) and again to close (ë7.9 + ‡5).
3.76/(ë7.9+(5))+2log(45)
log
requires ( ) around its
argument.
sin(
or
TI-89
or
from
Sin(
,
.

Entering Multiple Expressions on a Line

To enter more than one expression or instruction at a time, separate them with a colon by pressing
.
Displays last result only.
is displayed when you press
!
to store a value to a variable.
Chapter 2: Operating the Calculator 27
§
A

If an Entry or Answer Is Too Long for One Line

Note: When you scroll to
the right, 7 is displayed at the beginning of the line.
In the history area, if both the entry and its answer cannot be displayed on one line, the answer is displayed on the next line.
If an entry or answer is too long to fit on one line, úis displayed at the end of the line.
To view the entire entry or answer:
1. Press Cto move the cursor from the entry line up into the history
area. This highlights the last answer.
2. As necessary, use Cand Dto highlight the entry or answer you
want to view. For example, Cmoves from answer to entry, up through the history area.
3. Use Band Aor
2A
to scroll right and left.
2B
and
4. To return to the entry line,
press N.

Continuing a Calculation

Example

Stopping a Calculation

When you press
TI-89 / TI-92 Plus
¸
to evaluate an expression, the
leaves the expression on the entry line and highlights it. You can continue to use the last answer or enter a new expression.
If you press: The TI.89 / TI.92 Plus:
«, |, p, e Z
, or
§
,
Replaces the entry line with the variable which lets you use the last answer as the beginning of another expression.
ny other key Erases the entry line and begins a new entry.
Calculate
On the TI.89: On the TI.92 Plus: Display
3.76
2]5dd
«22™ c45d
¸
3.76 ÷ (ë7.9 + ‡5)
7.9
ec·
¸
LOG
«
j
. Then add
3.76
2]5dd
2 LOG
« c45d
¸
When a calculation is in progress,
ec·
BUSY
2 log 45
to the result.
7.9
«
¸
When you press «, the entry line is replaced with the variable ans(1), which contains the last answer.
appears on the right end of
the status line. To stop the calculation, press ´. There may be a delay before the “break”
message is displayed. Press Nto return to the current application.
ans(1)
,
28 Chapter 2: Operating the Calculator

Formats of Displayed Results

Pretty Print Mode

Exact/Approx Mode

Note: By retaining fractional
and symbolic forms, reduces rounding errors that could be introduced by intermediate results in chained calculations.
EXACT
A result may be calculated and displayed in any of several formats. This section describes the TI
-
89 / TI-92 Plus modes
and their settings that affect the display formats. To check or change your current mode settings, refer to page 40.
By default,
Pretty Print = ON
. Exponents, roots, fractions, etc., are displayed in the same form in which they are traditionally written. You can use 3to turn pretty print off and on.
Pretty Print
ON OFF
xì3
p
ñ
p
,
,
2
2
p
p
^2
/2
((xì3)/2)
,
,
The entry line does not show an expression in pretty print. If pretty print is turned on, the history area will show both the entry and its result in pretty print after you press
By default,
Exact/Approx = AUTO
¸
.
. You can use 3to select from
three settings. Because
AUTO
is a combination of the other two settings, you should be familiar with all three settings.
— Any result that is not a whole number is displayed in a
EXACT
fractional or symbolic form (
1/2
, p, 2, etc.).
Shows whole-number results.
Shows simplified fractional results.
Shows symbolic p. Shows symbolic form of roots that
cannot be evaluated to a whole number.
Press ¥ ¸ to temporarily override the display a floating-point result.
Chapter 2: Operating the Calculator 29
EXACT
setting and
Exact/Approx (continued)
Note: Results are rounded
to the precision of the
TI-89 / TI-92 Plus
displayed according to current mode settings.
and
APPROXIMATE
— All numeric results, where possible, are displayed
in floating-point (decimal) form.
Fractional results are evaluated numerically.
Symbolic forms, where possible, are evaluated numerically.
Tip: To retain an form, use fractions instead of decimals. For example, use 3/2 instead of 1.5.
Tip: To evaluate an entry in
APPROXIMATE
regardless of the current setting, press
EXACT
form,
¥¸
.
Because undefined variables cannot be evaluated, they are treated algebraically. For example, if the variable
p
rñ= 3.14159⋅r
— Uses the
AUTO
APPROXIMATE
certain functions may display
.
ñ
EXACT
form where possible, but uses the
form when your entry contains a decimal point. Also,
APPROXIMATE
r
results even if your
entry does not contain a decimal point.
A decimal in the entry forces a floating-point result.
The following chart compares the three settings.
Entry
Result
8/4 2 2. 2 8/6 4/3 1.33333 4/3
8.5ù3 51/2 25.5 25.5
(2)/2
p
22
ù
p
2. 2
ù
Exact
2
2
p
p
Approximate
Result
.707107
6.28319 2
6.28319 6.28319
Auto
Result
2
2
p
is undefined,
A decimal in the entry forces a floating-point
AUTO
result in
.
30 Chapter 2: Operating the Calculator

Display Digits Mode

Note: Regardless of the
Display Digits setting, the full value is used for internal floating-point calculations to ensure maximum accuracy.
Note: A result is automatically shown in scientific notation if its magnitude cannot be displayed in the selected number of digits.
By default,
Display Digits = FLOAT 6
, which means that results are rounded to a maximum of six digits. You can use 3to select different settings. The settings apply to all exponential formats.
Internally, the
TI-89 / TI-92 Plus
calculates and retains all decimal results with up to 14 significant digits (although a maximum of 12 are displayed).
Setting Example Description
FIX (0 – 12)
FLOAT 123.456789012
123. (FIX 0)
123.5 (FIX 1)
123.46 (FIX 2)
123.457 (FIX 3)
Results are rounded to the selected number of decimal places.
Number of decimal places varies, depending on the result.
FLOAT (1 – 12)
1.E 2 (FLOAT 1)
E
1.2
2 (FLOAT 2)
123. (FLOAT 3)
123.5 (FLOAT 4)
123.46 (FLOAT 5)
123.457 (FLOAT 6)
Results are rounded to the total number of selected digits.

Exponential Format Mode

Note: In the history area, a
number in an entry is displayed in its absolute value is less than .001.
SCIENTIFIC
if
By default,
Exponential Format = NORMAL
. You can use 3to select from three settings.
Setting Example Description
NORMAL 12345.6
If a result cannot be displayed in the number of digits specified by the
Display Digits
TI-89 / TI-92 Plus
NORMAL
to
result only.
SCIENTIFIC 1.23456E 4 1.23456 × 10
Exponent (power of 10). Always 1 digit to the left of the
decimal point.
E
ENGINEERING 12.3456
3 12.3456 × 10
Exponent is a multiple of 3. May have 1, 2, or 3 digits to the
left of the decimal point.
Chapter 2: Operating the Calculator 31
mode, the
switches from
SCIENTIFIC
4
3
for that
A
A

Editing an Expression in the Entry Line

A
B
Knowing how to edit an entry can be a real time-saver. If you make an error while typing an expression, it’s often easier to correct the mistake than to retype the entire expression.

Removing the Highlight from the Previous Entry

Moving the Cursor

Note: If you accidentally
instead of Aor B,
press
C
the cursor moves up into the history area. Press
until the cursor
press
D
returns to the entry line.
N
or

Deleting a Character

After you press
¸
to evaluate an expression, the
TI-89 / TI-92 Plus
leaves that expression on the entry line and highlights it. To edit the expression, you must first remove the highlight; otherwise, you may clear the expression accidentally by typing over it.
To remove the highlight, move the cursor toward the side of the expression you want to edit.
moves the cursor to the
end of the expression.
moves the cursor to the beginning.
After removing the highlight, move the cursor to the applicable position within the expression.
To move the cursor: Press:
Left or right within an expression.
or
B
Hold the pad to repeat the movement.
To the beginning of the expression. To the end of the expression.
To delete: Press:
The character to the
0
left of the cursor. The character to the
¥0
2A
2B
Hold 0to delete multiple characters.
right of the cursor.
ll characters to the
right of the cursor.
M
(once only)
If there are no characters to the right of the cursor,
M
erases
the entire entry line.

Clearing the Entry Line

To clear the entry line, press:
¦
M
if the cursor is at the beginning or end of the entry line.
— or —
¦
MM
if the cursor is not at the beginning or end of the entry line. The first press deletes all characters to the right of the cursor, and the second clears the entry line.
32 Chapter 2: Operating the Calculator

Inserting or Overtyping a Character

Tip: Look at the cursor to
see if you’re in insert or overtype mode.
The
TI-89 / TI-92 Plus
default, the the insert and overtype modes, press
If the TI.89 / TI.92 Plus is in: The next character you type:
has both an insert and an overtype mode. By
TI-89 / TI-92 Plus
is in the insert mode. To toggle between
2/
.
Will be inserted at the cursor.
Thin cursor between characters
Will replace the highlighted
Cursor highlights a character
character.

Replacing or Deleting Multiple Characters

Tip: When you highlight
characters to replace, remember that some function keys automatically add an open parenthesis.
First, highlight the applicable characters. Then, replace or delete all the highlighted characters.
To: Do this:
Highlight multiple characters
1. Move the cursor to either side of the characters you want to highlight.
sin(
To replace the cursor beside
with
sin
cos(
.
, place
2. Hold ¤and press Aor Bto highlight characters left or right of the cursor.
Hold ¤ and press B B B B.
Replace the
Type the new characters. highlighted characters
— or — Delete the
Press 0. highlighted characters
Chapter 2: Operating the Calculator 33

Menus

Displaying a Menu

To leave the keyboard uncluttered, the TI
-
89 / TI-92 Plus uses
menus to access many operations. This section gives an overview of how to select an item from any menu. Specific menus are described in the appropriate chapters of this guidebook.
Press: To display:
ƒ, „
,
etc.
A toolbar menu — Drops down from the toolbar at the top of most application screens. Lets you select operations useful for that application.
O
APPLICATIONS
menu — Lets you select from a list of
applications. Refer to page 38.
2¿
CHAR
menu — Lets you select from categories of
special characters (Greek, math, etc.).
2I
MATH
menu — Lets you select from categories of
math operations.
TI.89:
½
TI.92 Plus:
CATALOG
alphabetic list of the functions and instructions. Also lets you select user­defined functions or Flash application functions (if any have been defined or loaded).
CUSTOM
menu — Lets you select from a complete,
TI-89 / TI-92 Plus’s
built-in
menu — Lets you access a menu that you can customize to list any available function, instruction, or character. The
TI-89 / TI-92 Plus
a default custom menu, which you can modify or redefine. Refer to page 37 and to Chapter 17.
includes

Selecting an Item from a Menu

To select an item from the displayed menu, either:
¦
Press the number or letter shown to the left of that item. For a letter on the — or —
¦
Use the cursor pad Dand Cto highlight the item, and then press
¸
. (Note that pressing Cfrom the first item moves the
highlight to the last item, and vice versa.)
34 Chapter 2: Operating the Calculator
, press j and then a letter key.
TI-89
6
indicates that a menu will drop down
from the toolbar when you press „.
factor(
factor
, press 2 or D ¸.
To select This closes the menu and inserts the function at the cursor location.
Items Ending with
(Submenus)
ú
Note: Because of limited screen size, the overlaps these menus as:
TI-89

Items Containing “. . .” (Dialog Boxes)

If you select a menu item ending with ú, a submenu is displayed. You then select an item from the submenu.
For example, submenu that lets you select a specific List function.
indicates that you can use
ï
the cursor pad to scroll down for additional items.
List
displays a
For items that have a submenu, you can use the cursor pad as described below.
¦ To display the submenu for the highlighted item, press
B
.
(This is the same as selecting that item.)
¦ To cancel the submenu without making a selection, press
A
.
(This is the same as pressing N.)
¦ To wrap to the last menu item directly from the first menu item,
press C. To wrap to the first menu item directly from the last menu item, press D.
. . .
If you select a menu item containing “ box is displayed for you to enter additional information.
” (ellipsis marks), a dialog

Canceling a Menu

For example, displays a dialog box that prompts you to select a folder name and type a variable name.
After typing in an input box such as Variable, you must press ¸ twice to save the information and close the dialog box.
Save Copy As ...
"
indicates that you can press B to
display and select from a menu. An input box indicates that you
must type a value. (Alpha-lock is automatically turned on for the TI-89. See page 22.)
To cancel the current menu without making a selection, press N. Depending on whether any submenus are displayed, you may need to press Nseveral times to cancel all displayed menus.
Chapter 2: Operating the Calculator 35

Moving from One Toolbar Menu to Another

To move from one toolbar menu to another without making a selection, either:
¦ Press the key (
ƒ, „
, etc.) for the other toolbar menu.
— or —
¦ Use the cursor pad to move to the next (press
B
) or previous (press A) toolbar menu. Pressing Bfrom the last menu moves to the first menu, and vice versa.
When using B, be sure that an item with a submenu is not highlighted. If so, Bdisplays that item’s submenu instead of moving to the next toolbar menu.

Example: Selecting a Menu Item

Round the value of p to three decimal places. Starting from a clear entry line on the Home screen:
Number
since
MATH
menu.
1. Press
2. Press
2I
1
to display the
submenu. (Or press
to display the
¸
the first item is automatically highlighted.)
3
3. Press
DD
4. Press
¸
to select
¸
and
2T
b3 d
to evaluate the expression.
round
.)
. (Or press
and then
Selecting the function in Step 3 automatically
round(
typed entry line.
on the
36 Chapter 2: Operating the Calculator

Using the Custom Menu

u
-
The TI and off at any time. You can use the default custom menu or create your own as described in Chapter 17: Programming.
89 / TI-92 Plus has a custom menu that you can turn on

Turning the Custom Menu On and Off

Note: You can also turn the
custom menu on and off by entering
CustmOn
CustmOff
and pressing
Tip: A custom menu can give you quick access to commonly used items. Chapter 17 shows you how to create custom menus for the items you use most often.
or
in the entry line
.
¸
When you turn on the custom menu, it replaces the normal toolbar menu. When you turn it off, the normal menu returns. For example, from the Home screen’s normal toolbar menu, press 2
¾
to
toggle the custom menu on and off.
2 ¾
Home screen normal toolbar menu Custom menu
Unless the menu has been modified, the default custom menu appears.
Menu Function
ƒ
Var
f(x)
Solve
Unit
Symbol
Internat’l
2
TI.89: TI.92 Plus:
Tool
2 ‰
TI.89: TI.92 Plus:
Common variable names. Function names such as f(x), g(x), and f(x,y). Items related to solving equations.
Common units such as _m, _ft, and _l. Symbols such as #, ?, and ~. Commonly accented characters such as è, é,and ê.
ˆ
ˆ
ClrHome, NewProb
, and
CustmOff
.

Restoring the Default Custom Menu

Note: The previous custom
menu is erased. If that men was created with a program (Chapter 17), it can be recreated later by running the program again.
If a custom menu other than the default is displayed and you want to restore the default:
1. From the Home screen, use 2
¾
to turn off the custom
menu and display the Home screen’s normal toolbar menu.
2. Display the and select
2 ˆ
TI.89: TI.92 Plus:
Clean Up
3:Restore custom default
ˆ
toolbar menu,
.
This pastes the commands used to create the default menu into the entry line.
3. Press
¸
to execute the commands and restore the default.
Chapter 2: Operating the Calculator 37

Selecting an Application

The TI
-
solve and explore a variety of problems. You can select an application from a menu, or you can access commonly used applications directly from the keyboard.
89 / TI-92 Plus has different applications that let you
From the
APPLICATIONS
Note: To cancel the menu
without making a selection, press
N
Menu
.
1. Press Oto display a menu that lists the applications.
2. Select an application. Either:
¦ Use the cursor pad
D
or Cto highlight the application and then press
¸
.
— or —
¦ Press the number or letter for
that application.
Application: Lets you:
FlashApps Y= Editor
Window Editor
Graph Table
Data/Matrix Editor
Program Editor
Text Editor Numeric Solver
Home
Display a list of Flash applications, if any. Define, edit, and select functions or
equations for graphing (Chapters 6 – 11). Set window dimensions for viewing a graph
(Chapter 6). Display graphs (Chapter 6). Display a table of variable values that
correspond to an entered function (Chapter 13).
Enter and edit lists, data, and matrices. You can perform statistical calculations and graph statistical plots (Chapters 15 and 16).
Enter and edit programs and functions (Chapter 17).
Enter and edit a text session (Chapter 18). Enter an expression or equation, define
values for all but one variable, and then solve for the unknown variable (Chapter 19).
Enter expressions and instructions, and perform calculations.
38 Chapter 2: Operating the Calculator

From the Keyboard

You can access commonly used applications from the keyboard. On
for example, ¥ # is the same as pressing ¥ and then ƒ.
the
TI-89
This guidebook uses the notation ¥ #, similar to the notation used in second functions.
TI-89
Application: Press:
Home
TI.89: TI.92 Plus:
Y= Editor Window Editor¥ Graph Table Setup Table Screen¥
¥ #
$
¥ %
¥ &
'
"
¹ "
Applications listed above ƒ, „ etc., are printed in the same color as ¥.
WINDOW GRAPH TBLSet TABLEY=
F1 F2 F3 F4 F5
APPS
HOME
On the
TI-92 Plus
Applications
, applications are listed above the
Diamond key
Chapter 2: Operating the Calculator 39
QWERTY
keys.

Setting Modes

Modes control how numbers and graphs are displayed and interpreted. Mode settings are retained by the Constant Memoryé feature when the TI
89 / TI-92 Plus is turned off. All
-
numbers, including elements of matrices and lists, are displayed according to the current mode settings.

Checking Mode Settings

Indicates you can scroll down to see additional modes.

Changing Mode Settings

Tip: To cancel a menu and
return to the box without making a selection, press
MODE
N
dialog
.
Press
3
to display the
MODE
dialog box, which lists the modes
and their current settings.
There are three pages of mode listings. Press ƒ, „, or … to quickly display a particular page.
indicates that you can
!
press B or A to display and select from a menu.
Modes that are not currently valid are dimmed. For example,
Note:
on Page 2,
Split 2 App
is not valid when
Split Screen
=
FULL
. When you
scroll through the list, the cursor skips dimmed settings.
MODE
From the
dialog box:
1. Highlight the mode setting you want to change. Use Dor C(with
ƒ, „
, or ) to scroll through the list.
2. Press Bor Ato display a menu that lists the valid settings. The current setting is highlighted.
3. Select the applicable setting. Either:
¦ Use
D
or Cto highlight the setting and press
¸
.
— or —
¦ Press the number or letter for that setting.
4. Change other mode settings, if necessary.
5. When you finish all your changes, press changes and exit the dialog box.
Important:
If you press Ninstead of
dialog box, any mode changes you made will be canceled.
¸
¸
to save the
to exit the
MODE
40 Chapter 2: Operating the Calculator

Overview of the Modes

Note: For detailed
information about a particular mode, look in the applicable section of this guidebook.
Mode Description
Graph
Current Folder
Type of graphs to plot:
POLAR, SEQUENCE, 3D
Folder used to store and recall variables. Unless you have created additional folders, only the is available. Refer to “Using Folders to Store Independent Sets of Variables” in Chapter 5.
Display Digits
Maximum number of digits ( of decimal places ( result. Regardless of the setting, the total number of displayed digits in a floating-point result cannot exceed 12. Refer to page 31.
Angle
Units in which angle values are interpreted and displayed:
Exponential Format
Complex Format
Notation used to display results:
SCIENTIFIC
Format used to display complex results, if any:
REAL
(complex results are not displayed unless you
use a complex entry),
Vector Format
Pretty Print
Format used to display 2- and 3-element vectors:
RECTANGULAR, CYLINDRICAL
Turns the pretty print display feature Refer to page 29.
Split Screen
Splits the screen into two parts and specifies how the parts are arranged:
TOP-BOTTOM
Split 1 App
Application in the top or left side of a split screen. If you are not using a split screen, this is the current application.
Split 2 App
Application in the bottom or right side of a split screen. This is active only for a split screen.
Number of Graphs
Graph 2
For a split screen, lets you set up both sides of the screen to display independent sets of graphs.
Number of Graphs = 2
If the Split 2 part of the screen. Refer to Chapter 12.
Split Screen Ratio
Exact/Approx
Proportional sizes of the two parts of a split screen:
1:1, 1:2
, or
Calculates expressions and displays results in numeric form or in rational/symbolic form:
EXACT
, or
FUNCTION, PARAMETRIC
FIX
) displayed in a floating-point
RADIAN
, or
DEGREE
or
ENGINEERING
RECTANGULAR
FULL
LEFT-RIGHT
, or
, selects the type of graph in
2:1
. (
TI-92 Plus
APPROXIMATE
, or DE.
FLOAT
) or fixed number
.
NORMAL
. Refer to page 31.
, or
SPHERICAL
, or
OFF
(no split screen),
. Refer to Chapter 14.
only)
. Refer to page 29.
MAIN
,
POLAR
or ON.
AUTO
,
folder
.
.
,
Chapter 2: Operating the Calculator 41
Modes (continued)
Mode Description
Base
Unit System
Lets you perform calculations by entering numbers in
(DEC)
decimal Lets you enter a unit for values in an expression,
such as 6_m * 4_m or 23_m/_s * 10_s, convert values from one unit to another within the same category, and create your own user-defined units.
Custom Units
Lets you select custom defaults. The mode is dimmed until you select
Language
Lets you localize the several languages, depending on which language Flash applications are installed.
, hexadecimal
Unit System, 3:CUSTOM
(HEX)
TI-89 / TI-92 Plus
, or binary
.
into one of
(BIN)
form.
42 Chapter 2: Operating the Calculator

Using the Clean Up Menu to Start a New Problem

On the Home screen, the Clean Up toolbar menu lets you start a new calculation from a cleared state without resetting the
TI-89 / TI-92 Plus’s memory.

Clean Up Toolbar Menu

Tip: When defining a
variable that you want to retain, use more than one character in the name. This prevents it from being deleted inadvertently by
1:Clear a–z
Note: For information about checking and resetting memory or other system defaults, refer to Chapter 21.
.
From the Home screen, display the
TI.89: TI.92 Plus:
Menu Item Description
Clear a–z
ˆ
Clears (deletes) all single-character variable names
ˆ
2
in the current folder, unless the variables are locked or archived. You will be prompted to press confirm the action.
Single-character variable names are often used in symbolic calculations such as:
solve(aøxñ+bøx+c=0,x)
If any of the variables have already been assigned a value, your calculation may produce misleading results. To prevent this, you can select before beginning the calculation.
NewProb
Places
¸
press
NewProb
NewProb
in the entry line. You must then
to execute the command.
performs a variety of operations that let you begin a new problem from a cleared state without resetting the memory:
¦ Clears all single-character variable names in the
current folder (same as variables are locked or archived.
¦ Turns off all functions and stat plots (
) in the current graphing mode.
PlotsOff
Restore custom default
¦ Performs
ClrIO
If a custom menu other than the default is in effect, this lets you restore the default. Refer to page 37.
ClrDraw, ClrErr, ClrGraph, ClrHome
, and
ClrTable
Clean Up
.
menu by pressing:
1:Clear a–z
1:Clear a–z
), unless the
FnOff
¸
and
to
,
Chapter 2: Operating the Calculator 43

Using the Catalog Dialog Box

The CATALOG provides a way to access any built-in
TI-89 / TI-92 Plus command (functions and instructions) from
one convenient list. In addition, the CATALOG dialog box lets you select functions used in Flash applications or user-defined functions (if any have been loaded or defined).

Displaying the CATALOG

Selecting a Built-in Command from the
CATALOG
Note: The first time you
display the starts at the top of the list. The next time you display the list, it starts at the same place you left it.
Built-in list
, it
To display the
½
TI.89: TI.92 Plus:
CATALOG
The list of all pre-installed instructions)
ƒ
Help is reserved for a future online help Flash application.
Options that are not currently valid are dimmed. For
Note:
example, ƒ application. Flash application.
CATALOG
dialog box, press:
2 ½
defaults to
.
Defaults to
Built-in.
Help
is reserved for a future online help Flash
Flash Apps
Built-in
, which displays an alphabetic
TI-89 / TI-92 Plus
and † allow access to Flash application functions and User-Defined functions and programs.
commands (functions and
is dimmed if you have not installed a
User-Defined
is dimmed if you have not
created a function or a program.
When you select a command, its name is inserted in the entry line at the cursor location. Therefore, you should position the cursor as necessary before selecting the command.
1. Press:
½
TI.89: TI.92 Plus:
2. Press
2 ½
Built-in
.
¦
Commands are listed in alphabetical order. Commands that do not start with a letter (+, %, ‡, G, etc.) are at the end of the list.
¦
To exit the
CATALOG
without
selecting a command, press N.
44 Chapter 2: Operating the Calculator
D
Tip: From the top of the list,
to move to the
press
C
bottom. From the bottom,
to move to the top.
press
D
3. Move the úindicator to the command, and press
To move the ú indicator: Press or type:
One command at a time One page at a time To the first command that
begins with a specified letter
C
or
2D
or
2C
The letter key. (On the
press j first. If you do,
not
you need to press j or
2 ™
again before you can
type a letter.)
¸
.
TI-89
, do

Information about Parameters

Note: For details about the
parameters, refer to that command’s description in Appendix A.

Selecting a Flash Application Function

For the command indicated by ú, the status line shows the required and optional parameters, if any, and their type.
Indicated command and its parameters
Brackets [ ] indicate optional parameters.
From the example above, the syntax for
factor
(expression)
required
factor
is:
— or —
(expression,variable)
factor
optional
A Flash application may contain one or more functions. When you select a function, its name is inserted in the entry line at the cursor location. Therefore, you should position the cursor as necessary before selecting the function.
1. Press:
½
TI.89: TI.92 Plus:
2. Press applications are installed in the
2 ½
Flash Apps.
(This option is dimmed if no Flash
TI-89 / TI-92 Plus
¦
The list is alphabetized by function
.)
name. The left column lists functions. The right column lists the Flash application that contains the function.
¦
Information about a function is displayed in the status line.
¦
To exit without selecting a function, press N.
Chapter 2: Operating the Calculator 45
3. Move the úindicator to the function, and press
D
D
To move the ú indicator: Press or type:
One function at a time One page at a time To the first function that
begins with a specified letter
C
or
2D
or
2C
The letter key. (On the
press j first. If you do,
not
you need to press j or
2 ™
again before you can
type a letter.)
¸
.
TI-89
, do

Selecting a User-Defined Function or Program

Note: Use the VAR-LINK
screen to manage variables, folders, and Flash applications. See Chapter 21.
You can create your own functions or programs and then use
User-Defined
to access them. For instructions on how to create functions, see “Creating and Evaluating User-Defined Functions” in Chapter 5, and “Overview of Entering a Function” in Chapter 17. See Chapter 17 for instructions on how to create and run a program.
When you select a function or program, its name is inserted in the entry line at the cursor location. Therefore, you should position the cursor as necessary before selecting the function or program.
1. Press:
½
TI.89: TI.92 Plus:
2. Press
2 ½
User-Defined.
(This option is dimmed if you have not
defined a function or created a program.)
¦
The list is alphabetized by function / program name. The left column lists functions and programs. The right column lists the folder that contains the function or program.
¦
If the function or program’s first line is a comment, the comment text is displayed in the status line.
¦
To exit without selecting a function or program, press N.
3. Move the úindicator to the function or program, and press
To move the ú indicator: Press or type:
One function or program at a
or
C
¸
time One page at a time To the first function or
program that begins with a specified letter
2D
The letter key. (On the
not
you need to press j or
2 ™
2C
or
, do
TI-89
press j first. If you do,
again before you can
type a letter.)
.
46 Chapter 2: Operating the Calculator

Storing and Recalling Variable Values

When you store a value, you store it as a named variable. You can then use the name instead of the value in expressions. When the TI expression, it substitutes the variable’s stored value.
89 / TI-92 Plus encounters the name in an
-

Rules for Variable Names

Examples

Data Types

A variable name:
¦ Can use 1 to 8 characters consisting of letters and digits. This
includes Greek letters (but not p), accented letters, and international letters. Do not include spaces.
The first character cannot be a digit.
¦
Can use uppercase or lowercase letters. The names
aB22
, and
ab22
all refer to the same variable.
AB22, Ab22
¦ Cannot be the same as a name that is preassigned by the
TI-89 / TI-92 Plus
Built-in functions (such as
LineVert
System variables (such as
store graph-related values). Refer to Appendix B for a list.
Variable Description
myvar a Log Log1 3rdTotal circumfer
You can save any data types, refer to
Data Types Examples
Expressions Lists
Matrices
Character strings Pictures
. Preassigned names include:
) and instructions (such as
abs
). Refer to Appendix A.
xmin
and
xmax
, which are used to
OK OK Not OK, name is preassigned to the OK Not OK, starts with a digit. Not OK, more than 8 characters.
TI-89 / TI-92 Plus
getType()
2.54, 1.25í6, 2p, xmin/10, 2+3i, (xì2)ñ, 2/2 {2 4 6 8}, {1 1 2}
[1 0 0] “Hello”, “The answer is:”, “xmin/10”
data type as a variable. For a list of
in Appendix A. Some examples are:
1 0 0
,

3 4 6
function.
log
,
Functions
myfunc(arg), ellipse(x,y,r1,r2)
Chapter 2: Operating the Calculator 47
v
Storing a Value in a
g
Variable
Note:
use when typing variable names.
TI-89
as necessary
j
users should
1. Enter the value you want to store, which can be an expression.
2. Press §. The store symbol (!) is displayed.
3. Type the variable name.
4. Press
¸
.
To store to a variable temporarily, you can use the “with” operator. Refer to “Substituting Values and Setting Constraints” in Chapter 3.

Displaying a Variable

Note: Refer to Chapter 3 for
information about symbolic manipulation.

Using a Variable in an Expression

Tip: To view a list of existin
variable names, use
Chapter 21.
as described in

Recalling a Variable’s Value

1. Type the variable name.
2. Press
¸
.
If the variable is undefined, the variable name is shown in the result. In this example, the variable
a
is undefined. Therefore, it is used as a symbolic variable.
1. Type the variable name into the
expression.
2. Press
¸
expression.
to evaluate the
The variable’s value did not change.
If you want the result to replace the
ariable’s previous value, you must
store the result.
In some cases, you may want to use a variable’s actual value in an expression instead of the variable name.
1. Press
to display a dialog
box.
2. Type the variable name.
3. Press
¸
twice.
In this example, the value stored in
num1
will be inserted at the
cursor position in the entry line.
48 Chapter 2: Operating the Calculator

Reusing a Previous Entry or the Last Answer

You can reuse a previous entry by reexecuting the entry “as is” or by editing the entry and then reexecuting it. You can also reuse the last calculated answer by inserting it into a new expression.

Reusing the Expression on the Entry Line

Tip: Reexecuting an entry
“as is” is useful for iterative calculations that involve variables.
When you press ¸ to evaluate an expression, the
TI-89 / TI-92 Plus
leaves that expression on the entry line and highlights it. You can type over the entry, or you can reuse it as necessary.
For example, using a variable, find the square of
1, 2, 3
, etc.
As shown below, set the initial variable value and then enter the variable expression. Next, reenter to increment the variable and calculate the square.
On the TI.89: On the TI.92 Plus: Display
0
§ 2™ ¸
NUM
2™ 2Ë ¸
¸¸ ¸¸
NUM
j«1§
NUM
NUMZ2
0
§
NUM
¸
NUM«1 NUM
2Ë ¸
§
NUMZ2
Chapter 2: Operating the Calculator 49
Tip: Editing an entry lets
y
e
ou make minor changes without retyping the entire entry.
2
Using the equation
A=pr
, use trial and error to find the radius of a
circle that covers 200 square centimeters.
8
The example below uses
as the first guess and then displays the
answer in its approximate floating-point form. You can edit and
7.95
reexecute using
and continue until the answer is as accurate as
you want.
On the TI.89: On the TI.92 Plus: Display
8
§jR2Ë
ãpäjRZ2
2 ¸
8§R
2TRZ ¸
2
Note: When the entry contains a decimal point, th result is automatically displayed in floating-point.

Recalling a Previous Entry

Note: You can also use the entry function to recall any
previous entry. Refer to entry() in Appendix A.
¥¸
A¥8
7.95
¸
¥¸
A¥.
7.95
¸
You can recall any previous entry that is stored in the history area, even if the entry has scrolled off the top of the screen. The recalled entry
whatever is currently shown on the entry line. You can
replaces
then reexecute or edit the recalled entry.
To recall: Press: Effect:
The last entry (if you’ve changed the entry line)
Previous entries
once
repeatedly
If the last entry is still shown on the entry line, this recalls the entry prior to that.
Each press recalls the entry prior to the one shown on the entry line.
For example:
If the entry line contains the last entry, 2 recalls this entry.
If the entry line is edited or cleared, 2 recalls this entry.
²
²
50 Chapter 2: Operating the Calculator

Recalling the Last Answer

Each time you evaluate an expression, the
ans(1)
answer to the variable
press
.
. To insert this variable in the entry line,
TI-89 / TI-92 Plus
stores the
For example, calculate the area of a garden plot that is 1.7 meters by
4.2 meters. Then calculate the yield per square meter if the plot produces a total of 147 tomatoes.
1. Find the area.
1.7
4.2
¸
p
2. Find the yield.
147
e2±¸
Variable ans(1) is inserted, and its value is used in the calculation.
Note: Refer to ans() in Appendix A.
ans(1)
Just as
always contains the last answer, also contain previous answers. For example, next-to-last answer.
ans(2), ans(3)
ans(2)
contains the
, etc.,
Chapter 2: Operating the Calculator 51
I
R
p

Auto-Pasting an Entry or Answer from the History Area

You can select any entry or answer from the history area and “auto-paste” a duplicate of it on the entry line. This lets you insert a previous entry or answer into a new expression without having to retype the previous information.

Why Use Auto-Paste

Note: You can also paste
information by using the
toolbar menu. Refer to
ƒ
“Cutting, Copying, and Pasting Information” in Chapter 5.

Auto-Pasting an Entry or Answer

Tip: To cancel auto-paste
and return to the entry line, press
Tip: To view an entry or answer too long for one line (indicated by úat the end of the line), use
2B
.
N
B
and 2A.
and Aor
The effect of using auto-paste is similar to
and
described in the previous section, but there are differences.
For entries:
For answers:
Pasting lets you: lets you:
any previous
nsert
entry into the entry line.
Pasting lets you: lets you:
Insert the displayed value of
any
revious answer
into the entry line.
the contents of the
eplace
entry line with any previous entry.
Insert the variable which contains
answer only
the last
. Each time you
enter a calculation,
ans(1)
ans(1)
,
is
updated to the latest answer.
1. On the entry line, place the cursor where you want to insert the
entry or answer.
2. Press Cto move the cursor up into the history area. This
highlights the last answer.
3. Use Cand Dto highlight the entry or answer to auto-paste.
C
¦
moves from answer to entry up through the history area.
¦ You can use
C
to highlight items that have scrolled off the screen.
4. Press
¸
.
The highlighted item is inserted in the entry line.
as
This pastes the entire entry or answer. If you need only a part of the entry or answer, edit the entry line to delete the unwanted parts.
52 Chapter 2: Operating the Calculator
A

Status Line Indicators in the Display

The status line is displayed at the bottom of all application screens. It shows information about the current state of the
TI-89 / TI-92 Plus, including several important mode settings.

Status Line Indicators

Modifier
Folder
Indicator Meaning
Current Folder
Key
Angle Mode
Exact/Approx
Mode
Shows the name of the current folder. Refer to “Using Folders to Store Independent Sets of Variables” in Chapter 5. that is set up automatically when you use the
TI-89 / TI-92 Plus
Modifier Key Shows which modifier key is in effect, as described
below.
2nd
2
— will use the second function of the next key
you press.
2
¥
— will use the diamond feature of the next key
you press.
(TI-89)
j
— will type the lowercase letter for the next
key you press.
(TI-89)
2 ™
— lowercase alpha-lock is on. Until you turn this off, will type the lowercase letter for each key you press. To cancel alpha-lock, press j.
(TI-89)
¤ j
— uppercase ALPHA-lock is on. Until you turn this off, will type the uppercase letter for each key you press. To cancel ALPHA-lock, press j.
¤
+
— will type the uppercase letter for the next key you press. On the letter without having to use j.
ngle
Mode
Shows the units in which angle values are interpreted and displayed. To change the mode, use the 3key.
RAD DEG
Radians Degrees
Note: To cancel 2, ¥,
j
key again or press a different modifier key.
Note: If the next key you press does not have a diamond feature or an associated letter, the key performs its normal operation.
, or
¤
,
press the same
Current
Graph Number (G#1 on the TI-92 Plus)
.
TI-89
Replace
Batteries
Graph
Mode
MAIN
History Pairs,
Busy/Pause,
Locked Variable
is the default folder
, you can use ¤ to type a
Angle
Chapter 2: Operating the Calculator 53
A
A
Œ
Status Line (continued)
Indicator Meaning
Exact/
pprox
Mode
AUTO
EXACT
APPROX
Graph Number
Shows how answers are calculated and displayed. Refer to page 29. To change the use the 3key.
Auto Exact Approximate
If the screen is split to show two independent graphs, this indicates which graph is active — (Displays
Graph Mode
FUNC y(x)
PAR x(t)
POL r(q)
SEQ u(n)
3D z(x,y) DE y'(t)
Battery
Indicates the type of graphs that can be plotted. To change the
functions
and
polar equations
sequences
3D equations
differential equations
Displayed only when the batteries are getting low. If
BATT
is shown with a black background, change the
batteries as soon as possible.
History Pairs, Busy/Pause,
The information shown in this part of the status line depends on the application you are using.
rchived
23/30
Displayed on the Home screen to show the number of entry/answer pairs in the history area. Refer to page 24.
BUSY
PAUSE
A calculation or graph is in progress. You paused a graph or program. The variable opened in the current editor
(Data/Matrix Editor, Program Editor, or Text Editor) is locked or archived and cannot be modified.
G#1
G#2
or
on the
Graph
mode, use the 3key.
y(t)
parametric equations
Exact/Approx
TI-92 Plus
GR1
.)
mode,
GR2
or
.
54 Chapter 2: Operating the Calculator

Finding the Software Version and ID Number

In some situations, you may need to find out information about your TI
89 / TI-92 Plus, particularly the software version and the
-
unit’s ID number.

Displaying the “About” Screen

When Do You Need this Information?

From the Home screen, press
ƒ
and then select
Your screen will be different than the one shown to the right.
¸
Press screen.
The information on the such as:
¦ If you obtain new or upgraded software for your
you may need to provide your current software version and/or the ID number of your unit.
¦ If you have difficulties with your
contact technical support, knowing the software version may make it easier to diagnose the problem.
A:About
.
or N to close the
About
screen is intended for situations
TI-89 / TI-92 Plus
TI-89 / TI-92 Plus
and need to
,
Chapter 2: Operating the Calculator 55
56 Chapter 2: Operating the Calculator

Chapter 3: Symbolic Manipulation

Preview of Symbolic Manipulation........................................................ 58
Using Undefined or Defined Variables.................................................. 59
Using Exact, Approximate, and Auto Modes ....................................... 61
Automatic Simplification......................................................................... 64
3
Delayed Simplification for Certain Built-In Functions........................ 66
Substituting Values and Setting Constraints ........................................ 67
Overview of the Algebra Menu............................................................... 70
Common Algebraic Operations .............................................................. 72
Overview of the Calc Menu..................................................................... 75
Common Calculus Operations................................................................ 76
User-Defined Functions and Symbolic Manipulation ......................... 77
If You Get an Out-of-Memory Error....................................................... 79
Special Constants Used in Symbolic Manipulation ............................. 80
This chapter is an overview of the fundamentals of using symbolic manipulation to perform algebraic or calculus operations.
You can easily perform symbolic calculations from the Home screen.
Chapter 3: Symbolic Manipulation 57

Preview of Symbolic Manipulation

Solve the system of equations 2x ì3y = 4 and ëx + 7y = ë12. Solve the first equation so that x is expressed in terms of y. Substitute the expression for x into the second equation, and solve for the value of y. Then substitute the y value back into the first equation to solve for the value of x.
Steps
1. Display the Home screen and clear the entry line. Solve the equation
2x ì3y = 4
„ 1 selects
menu. You can also type directly from the keyboard or select it from the
for x.
solve(
Catalog
from the
.
Algebra
solve(
2. Begin to solve the equation
x + 7y = ë12
ë
press
¸
yet.
for y, but do not
3. Use the “with” operator to substitute the expression for
x
that was calculated from the first equation. This gives the
y
value of
The “with” operator is displayed as
on the screen.
Use the auto-paste feature to
highlight the last answer in the history area and paste it to the entry line.
.
4. Highlight the equation for x in the history area.
Keystrokes
" MM
1
2X|3YÁ4
bXd¸
1
·X«7YÁ
·12bYd
Í C¸ ¸
|
CCC
³
TI.89
TI.92 Plus
Keystrokes Display
¥" MM
1
2X|3YÁ4
bXd¸
1
·X«7YÁ
·12bYd
2Í C¸ ¸
CCC
5. Auto-paste the highlighted expression to the entry line. Then substitute the value of that was calculated from the
¸ Í C¸
y
¸
¸ 2Í C¸ ¸
second equation.
The solution is:
x = ë8/11
and
y = ë20/11
This example is a demonstration of symbolic manipulation. A one-step function is available for solving systems of equations. (See page 73.)
58 Chapter 3: Symbolic Manipulation

Using Undefined or Defined Variables

When performing algebraic or calculus operations, it is important that you understand the effect of using undefined and defined variables. Otherwise, you may get a number for a result instead of the algebraic expression that you anticipated.

How Undefined and Defined Variables Are Treated

Tip: When defining a
variable, it’s a good practice to use more than one character in the name. Leave one-character names undefined for symbolic calculations.

Determining If a Variable Is Undefined

When you enter an expression that contains a variable, the
TI-89 / TI-92 Plus
¦
If the variable is
treats the variable in one of two ways.
undefined, it is treated as an algebraic symbol.
¦
If the variable is defined (even if defined as 0), its value replaces the variable.
To see why this is important, suppose you want to find the first
x
derivative of
¦
If x is undefined, the
with respect to x.
ò
result is in the form you probably expected.
¦
If x is defined, the result may be in a form you did not expect.
Method: Example:
Unless you knew that 5 had been stored to x previously, the answer 75 could be misleading.
If defined, the variable’s value is displayed.
Enter the variable name.
Note: Use view a list of defined variables, as described in Chapter 21.
to
Use the
getType
If undefined, the variable name is displayed.
If defined, the variable’s type is displayed.
function.
If undefined, “ displayed.
Chapter 3: Symbolic Manipulation 59
NONE
” is
v A

Deleting a Defined Variable

You can “undefine” a defined variable by deleting it.
To delete: Do this:
One or more specified
Use the
DelVar
function.
ariables
Note: For information about folders, refer to Chapter 5.

Temporarily Overriding a Variable

Note: For more information
about the page 67.
operator, refer to
|
You can also delete variables by using the
VAR-LINK
screen (
described in Chapter 21.
ll one-letter variables
a
– z) in the current
( folder
From the Home screen
Clear a-z
select 1:
¸
press
to confirm the deletion.
By using the “with” operator ( | ), you can:
¦
Temporarily override a variable’s defined value.
¦
Temporarily define a value for an undefined variable.
To type the “with” operator ( | ), press:
Í
TI.89: TI.92 Plus:
2 Í
Clean Up
) as
menu,
. You will be prompted to
60 Chapter 3: Symbolic Manipulation

Using Exact, Approximate, and Auto Modes

The Exact/Approx mode settings, which are described briefly
EXACT
Setting
in Chapter 2, directly affect the precision and accuracy with which the TI describes these mode settings as they relate to symbolic manipulation.
When arithmetic with up to 614 digits in the numerator and 614 digits in the denominator. The
¦
Transforms irrational numbers to standard forms as much as possible without approximating them. For example, transforms to
¦
Converts floating-point numbers to rational numbers. For example,
The functions use only exact symbolic algorithms. These functions do not compute approximate solutions in the
¦
Some equations, such as finitely represented in terms of the functions and operators on the
TI-89 / TI-92 Plus
¦
With this kind of equation, solutions. For example,
x ≈ 0.641186
-
89 / TI-92 Plus calculates a result. This section
Exact/Approx = EXACT
EXACT
2
0.25
transforms to
solve, cSolve, zeros, cZeros, factor,
3
and
, the
setting:
ln(1000)
EXACT 2–x = x
.
EXACT
2–x = x
, but it is not displayed in the
TI-89 / TI-92 Plus
transforms to
1/4
.
setting.
, have solutions that cannot all be
will not compute approximate
has an approximate solution
uses exact rational
12
3 ln(10)
.
,
, and
fMin
EXACT
setting.
fMax
Advantages Disadvantages
Results are exact. As you use more complicated rational
numbers and irrational constants, calculations can:
¦
Use more memory, which may exhaust the memory before a solution is completed.
¦
Take more computing time.
¦
Produce bulky results that are harder to comprehend than a floating-point number.
Chapter 3: Symbolic Manipulation 61
A
APPROXIMATE
Setting
Exact/Approx = APPROXIMATE
When
, the
TI-89 / TI-92 Plus
converts rational numbers and irrational constants to floating-point. However, there are exceptions:
¦
Certain built-in functions that expect one of their arguments to be an integer will convert that number to an integer if possible. For example: d
¦
Whole-number floating-point exponents are converted to integers.
(y(x), x, 2.0)
For example:
transforms to d
2.0
x
transforms to
(y(x), x, 2)
2
x
even in the
.
APPROXIMATE
setting.
Functions such as
solve
and
(integrate)
can use both exact symbolic and approximate numeric techniques. These functions skip all or some of their exact symbolic techniques in the
APPROXIMATE
setting.
Advantages Disadvantages
If exact results are not needed, this might save time and/or use less memory than the
EXACT
setting.
pproximate results are sometimes more compact and comprehensible than exact results.
If you do not plan to use symbolic computations, approximate results are
Results with undefined variables or functions often exhibit incomplete cancellation. For example, a coefficient
0
that should be small magnitude such as
might be displayed as a
1.23457E-11
.
Symbolic operations such as limits and integration are less likely to give satisfying results in the
APPROXIMATE
setting.
Approximate results are sometimes less compact and comprehensible than exact results. For example, you may prefer to see
1/7
instead of
.142857
. similar to familiar, traditional numeric calculators.
62 Chapter 3: Symbolic Manipulation
AUTO
Setting
Exact/Approx = AUTO
When
, the
TI-89 / TI-92 Plus
uses exact rational arithmetic wherever all of the operands are rational numbers. Otherwise, floating-point arithmetic is used after converting any rational operands to floating-point. In other words, floating-point is “infectious.” For example:
1/2 − 1/3
transforms to
1/6
but
0.5 − 1/3
transforms to
.16666666666667
This floating-point infection does not leap over barriers such as undefined variables or between elements of lists or matrices. For example:
(1/2 - 1/3) x + (0.5 − 1/3) y
transforms to
x/6 + .16666666666667 y
and
{1/2 - 1/3, 0.5 − 1/3}
AUTO
In the
setting, functions such as
transforms to
{1/6, .16666666666667}
determine as many
solve
solutions as possible exactly, and then use approximate numerical methods if necessary to determine additional solutions. Similarly,
(integrate)
uses approximate numerical methods if appropriate
where exact symbolic methods fail.
Advantages Disadvantages
You see exact results when practical, and approximate numeric results when exact results are impractical.
You can often control the format of a result by choosing to enter some
If you are interested only in exact results, some time may be wasted seeking approximate results.
If you are interested only in approximate results, some time may be wasted seeking exact results. Moreover, you might exhaust the memory seeking those
exact results. coefficients as either rational or floating-point numbers.
Chapter 3: Symbolic Manipulation 63

Automatic Simplification

When you type an expression on the entry line and press
¸
, the
expression according to its default simplification rules.
TI-89 / TI-92 Plus automatically simplifies the

Default Simplification Rules

Note: For information about
folders, refer to Chapter 5.
Note: Refer to “Delayed Simplification for Certain Built-In Functions” on page 66.
All of the following rules are applied automatically. You do not see intermediate results.
¦ If a variable has a defined value, that value replaces the variable.
If the variable is defined in terms of another variable, the variable is replaced with its “lowest level” value (called infinite lookup).
Default simplification does not modify variables that use path names to indicate a folder. For example,
2x
simplify to
.
x+class\x
does not
¦ For functions:
The arguments are simplified. (Some built-in functions delay
simplification of some of their arguments.)
If the function is a built-in or user-defined function, the
function definition is applied to the simplified arguments. Then the functional form is replaced with this result.
¦ Numeric subexpressions are
combined.
¦ Products and sums are sorted
into order.
Products and sums involving undefined variables are sorted according to the first letter of the variable name.
Undefined variables
r
through z are assumed to be true variables, and are placed in alphabetical order at the beginning of a sum.
a
Undefined variables
through q are assumed to represent constants, and are placed in alphabetical order at the end of a sum (but before numbers).
¦ Similar factors and similar terms
are collected.
64 Chapter 3: Symbolic Manipulation
This floating-point number causes numeric results to be shown as floating-point.
If a floating-point whole number is entered as an exponent, it is treated as an integer (and does not produce a floating-point result).
¦
Identities involving zeros and ones are exploited.
¦ Polynomial greatest common
divisors are canceled.
¦ Polynomials are expanded unless
no key cancellation can occur.
¦ Common denominators are
formed unless no key cancellation can occur.
¦ Functional identities are
exploited. For example:
ln(2x) = ln(2) + ln(x)
and
sin(x)ñ+ cos(x)ñ= 1
No key cancellation
No key cancellation

How Long Is the Simplification Process?

Depending on the complexity of an entry, result, or intermediate expression, it can take a long time to expand an expression and cancel common divisors as necessary for simplification.
To interrupt a simplification process that is taking too long, press ´. You can then try simplifying only a portion of the expression. (Auto-paste the entire expression on the entry line, and then delete the unwanted parts.)
Chapter 3: Symbolic Manipulation 65

Delayed Simplification for Certain Built-In Functions

Usually, variables are automatically simplified to their lowest possible level before they are passed to a function. For certain functions, however, complete simplification is delayed until after the function is performed.

Functions that Use Delayed Simplification

Note: Not all functions that
use a var argument use delayed simplification.
Note: You may or may not want to define a numeric value for var, depending on the situation.
Note: The example to the right finds the derivative of xòat x=5. If xòwas initially simplified to 75, you would find the derivative of 75, which is not what you want.
Functions that use delayed simplification have a required
var
argument that performs the function with respect to a variable. These functions have at least two arguments with the general form:
expression, var
(
function
For example:
solve
d(x ^2
(x^2ìxì2,x)
(x
limit
(x^2
ìxì
ñ
[, ... ]
ìxì
ìxì
)
2=0,x)
2,x)
2,x,5)
For a function that uses delayed simplification:
1. The
variable is simplified to the lowest level at which it
var
remains a variable (even if it could be further simplified to a non-variable value).
2. The function is performed using the variable.
3. If
can be further simplified, that value is then substituted into
var
the result.
For example:
x cannot be simplified.
x is not simplified. The function uses xò, and then substitutes 5 for x.
x is simplified to t. The function uses tò.
x is simplified to t. The function uses tò, and then substitutes 5 for t.
66 Chapter 3: Symbolic Manipulation
v
v
v
v

Substituting Values and Setting Constraints

The “with” operator ( | ) lets you temporarily substitute values into an expression or specify domain constraints.

Typing the “With” Operator

Substituting for a Variable

Substituting for a Simple Expression

Note:
from
acos(x)
a*cos(x)
is different
.
To type the “with” operator ( | ), press:
Í
TI.89: TI.92 Plus:
2 Í
For every occurrence of a specified variable, you can substitute a numeric value or an expression.
To substitute for multiple
ariables at the same time, use
the Boolean
and
operator.
For every occurrence of a simple expression, you can substitute a
ariable, numeric value, or
another expression.
By replacing a commonly used (or long) term, you can display results in a more compact form.
First derivative of xìò at x = 5
Substituting s for sin(x) shows that the expression is a polynomial in terms of sin(x).

Substituting Complex Values

You can substitute complex
alues just as you would for other alues.
Note: For an overview of complex numbers, refer to Appendix B.
Tip: To get the complex press type the letter i on the keyboard.
2)
.
Do not simply
All undefined variables are treated as real numbers in symbolic calculations. To perform complex symbolic analysis, you must define a complex variable. For example:
,
i
x+yi
z
!
Then you can use z as a complex variable. You can also use z_. For more information see the _ (underscore) topic in Appendix A.
Chapter 3: Symbolic Manipulation 67

Be Aware of the Limitations of Substitutions

¦
Substitution occurs only where there is an
exact
Only x2 was replaced, not x4.
match for the substitution.
Define the substitution in simpler terms for a more complete substitution.
¦ Infinite recursions can occur when you define a substitution
variable in terms of itself.
Substitutes sin(x+1), sin(x+1+1), sin(x+1+1+1), etc.
sin(x)|x=x+1
When you enter a substitution that causes an infinite recursion:
An error message is
displayed.
Tip: Use the solve function to help determine the single­variable substitution.
When you press
N
, an error is shown in the history area.
¦ Internally, an expression is sorted according to the automatic
simplification rules. Therefore, products and sums may not match the order in which you entered them.
As a general rule, you
should substitute for a single variable.
Substituting for more
general expressions
møcñ=e
(either
cñøm=e
or
) may not work
as you anticipate.
No match for substitution
68 Chapter 3: Symbolic Manipulation
Specifying Domain
f
Constraints
Tip: Enter
ln(xy)
interpreted as a single variable named xy.
Tip: For ‚ or , press or ¥Â. You can also use
2I
select them from a menu.
ln(xùy)
8
or
instead o
2¿
; otherwise, xy is
¥Ã
2
Many identities and transformations are valid for only a particular domain. For example:
ln(xùy) = ln(x) + ln(y) sinê(sin(q)) =
q
only if x and/or y is not negative
ë
only if q ‚
p
/2
and q 
p
/2
radians
Use the “with” operator to specify the domain constraint.
Because ln(xùy) = ln(x) + ln(y) is not always valid, the logarithms are not combined.
With a constraint, the identity is valid and the expression is simplified.
Because sinê(sin(q)) = q is not always valid, the expression is not simplified.
to
With a constraint, the expression can be simplified.

Using Substitutions vs. Defining a Variable

Caution: After x is defined,
it can affect all calculations that involve x (until you delete x).
In many cases, you can achieve the same effect as a substitution by defining the variable.
However, substitution is preferable for most cases because the variable is defined only for the current calculation and does not accidentally affect later calculations.
Substituting x=1 does not affect the next calculation.
Storing 1!x affects the subsequent calculations.
Chapter 3: Symbolic Manipulation 69

Overview of the Algebra Menu

The Algebra Menu

Note: For a complete
description of each function and its syntax, refer to Appendix A.
You can use the „
Algebra
toolbar menu to select the most
commonly used algebraic functions.
From the Home screen, press „ to display:
This menu is also available from the menu. Press
9:Algebra
Menu Item Description
solve
Solves an expression for a specified variable. This
2I
.
returns real solutions only, regardless of the
factor
Complex Format
and
" and "or" connecting solutions. (For complex
" solutions, select
Factors an expression with respect to all its
mode setting. Displays answers with
A:Complex
variables or with respect to only a specified variable.
expand
Expands an expression with respect to all its variables or with respect to only a specified variable.
zeros
Determines the values of a specified variable that make an expression equal to zero. Displays in a list.
approx
Evaluates an expression using floating-point arithmetic, where possible. This is equivalent to
Exact/Approx = APPROXIMATE
¥¸
to evaluate an expression).
comDenom
using 3 to set (or using
Calculates a common denominator for all terms in an expression and transforms the expression into a reduced ratio of a numerator and denominator.
propFrac
Returns an expression as a proper fraction expression.
nSolve
Calculates a single solution for an equation as a floating-point number (as opposed to may display several solutions in a rational or symbolic form).
and then select
from the
Algebra
solve
MATH
menu.)
, which
70 Chapter 3: Symbolic Manipulation
Menu Item Description
Trig
Displays the submenu:
Note: The functions are also used to return a specified number of elements or characters from the left or right side of a list or character string.
left
and
right
Complex
Extract
tExpand
Expands trig expressions with angle sums and multiple angles.
tCollect
Collects the products of integer powers of trig functions into angle sums and multiple angles.
tExpand
tCollect
.
Displays the submenu:
These are the same as
solve, factor
they also compute complex results.
Displays the submenu:
getNum
Applies
comDenom
and then returns the
resulting numerator.
getDenom
Applies
comDenom
and then returns the
resulting denominator.
left
Returns the left-hand side of an equation or inequality.
right
Returns the right-hand side of an equation or inequality.
is the opposite of
, and
zeros
; but
Chapter 3: Symbolic Manipulation 71
v

Common Algebraic Operations

Adding or Dividing Polynomials

Factoring and Expanding Polynomials

Finding Prime Factors of a Number

This section gives examples for some of the functions
Algebra
available from the
toolbar menu. For complete information about any function, refer to Appendix A. Some algebraic operations do not require a special function.
You can add or divide polynomials directly, without using a special function.
Use the
factor
expand
Factor
2
(
) and
factor
(expression [,var])
5
x
(expression [,var])
1
. Then expand the
ì
expand
for factoring with respect to a variable
3
(
) functions.
for partial expansion with respect to a variable
result.
Notice that
factor
and
expand
perform opposite operations.
The
factor
2
(
) function lets you do more than simply factor an
algebraic polynomial.
You can find prime factors of a rational number (either an integer or a ratio of integers).

Finding Partial Expansions

With the
expand
partial expansion that collects similar powers of a variable.
Do a full expansion of
(yñìy)
with respect to all
3
(
) function’s optional
(xñìx)
value, you can do a
var
ariables.
Then do a partial expansion with respect to x.
72 Chapter 3: Symbolic Manipulation

Solving an Equation

Note: An operation such as
2
subtracts 2x from
|
Ù
both sides.
1
Use the
solve
(
) function to solve an equation for a specified
variable.
(equation, var)
solve
x + y ì5 = 2x ì5y
Solve for x.
Notice that
solve
displays
only the final result.
To see intermediate results, you can manually solve the equation step-by-step.
x « y | 5 Á 2x | 5y
2 x
|
y
|
5
«
1
p ·

Solving a System of Linear Equations

Note: The
matrix functions are not on
Algebra
the
2I
simult
4
or the
and
rref
menu. Use
Catalog.
Consider a set of two equations with two unknowns:
2x ì3y = 4
x + 7y = ë12
ë
To solve this system of equations, use any of the following methods.
Method Example
Use the
solve
function
2xì3y=4 and ëx+7y=ë12,{x,y}
solve
(
)
for a one-step solution.
Use the with substitution ( | ) for step-by-step
solve
function
Refer to the preview at the beginning of this chapter, which solved for
y = ë20/11
and
.
x = ë8/11
manipulation.
Use the with a matrix.
Use the with a matrix.
simult
function
rref
function
Enter the coefficients as a matrix and the results as a constant column matrix.
Enter the coefficients as an augmented matrix.
Chapter 3: Symbolic Manipulation 73

Finding the Zeros of an Expression

Use the
zeros
4
(
zeros
(expression, var)
) function.
Tip: For ‚ or , type
.You can also use
¥ Â
8
2I
select them from a menu.
or
2¿
¥ Ã

Finding Proper Fractions and Common Denominators

Note: You can use
comDenom
expression, list, or matrix.
with an
or
Use the expression
x ùsin(x) + cos(x)
2
to
Find the zeros with respect to in the interval
Use the
propFrac
comDenom
0  x
propFrac
(rational expression [,var])
(expression [,var])
Find a proper fraction for the expression
4
(x
+ x) / (2xñ+ x + 4)
ì2xñ
Then transform the answer into a ratio of a fully expanded numerator and a fully expanded denominator.
Notice that
comDenom
propFrac
perform opposite
operations.
In this example:
31 x + 60
¦
x
¦
is the remainder of
8
ñ
x
ì
ì
15/8
4
2
.
x  3
(
and
7
) and
.
.
and
is the quotient.
x
Use the “with” operator to specify the interval.
6
(
) functions.
comDenom
for common denominators that collect
for common denominators that collect similar powers of this variable
similar powers of this variable
If you do this example on your
TI-89 / TI-92 Plus, the
function scrolls off the top of the
screen.
4
x
ì2xñ
for proper fractions with respect to a variable
propFrac
+x
divided by
2xñ+x+4
.
74 Chapter 3: Symbolic Manipulation

Overview of the Calc Menu

s

The Calc Menu

Note: For a complete
description of each function and its syntax, refer to Appendix A.
d
Note: The differentiate is a special symbol. It is not the same a typing keyboard. Use
2 =
symbol for
the letter D
.
on the
1
or
You can use the …
Calc
toolbar menu to select commonly
used calculus functions.
From the Home screen, press … to display:
This menu is also available from the
2I
.
Menu Item Description
differentiate
d
Differentiates an expression with respect to a
menu. Press
A:Calculus
specified variable.
integrate
Integrates an expression with respect to a specified variable.
limit
Calculates the limit of an expression with respect to a specified variable.
G
sum
Evaluates an expression at discrete variable values within a range and then calculates the sum.
product
Π
Evaluates an expression at discrete variable values within a range and then calculates the product.
fMin
Finds candidate values of a specified variable that minimize an expression.
fMax
Finds candidate values of a specified variable that maximize an expression.
arcLen
Returns the arc length of an expression with respect to a specified variable.
taylor
Calculates a Taylor polynomial approximation to an expression with respect to a specified variable.
nDeriv
Calculates the numerical derivative of an expression with respect to a specified variable.
nInt
Calculates an integral as a floating-point number using quadrature (an approximation using weighted sums of integrand values).
deSolve
Symbolically solves many 1st and 2nd order differential equations, with or without initial conditions.
and then select
MATH
Chapter 3: Symbolic Manipulation 75

Common Calculus Operations

Integrating and Differentiating

You can integrate an
Note:
expression only; you can differentiate an expression, list, or matrix.

Finding a Limit

You can find a limit
Note:
for an expression, list, or matrix.
This section gives examples for some of the functions available from the …
Calc
toolbar menu. For complete
information about any calculus function, refer to Appendix A.
Use the
Integrate to
integrate
(expression, var [,low] [,up])
(expression, var [,order])
d
xñùsin(x)
x
.
(
with respect
2
) and d
differentiate
lets you specify limits or a constant of integration
(
1
) functions.
Differentiate the answer with respect to x.
To get d, use … 1 or 2 =. Do not simply type the letter D on the keyboard.
Use the
limit
(expression, var, point [,direction])*
limit
Find the limit of
(
3
) function.
sin(3x) / x
as
negative = from left positive = from right omitted or 0 = both
x
approaches 0.
Use the

Finding a Taylor Polynomial

Important:
scaling by p/180 may cause calculus application results to appear in a different form.
Degree-mode
taylor
(expression, var, order [,point])
taylor
Find a 6th order Taylor polynomial for respect to
Store the answer as a user­defined function named
Then graph polynomial.
76 Chapter 3: Symbolic Manipulation
(
sin(x)
x
.
sin(x)
and the Taylor
9
) function.
with
y1(x)
if omitted, expansion point is 0
.
Graph sin(x):Graph y1(x)

User-Defined Functions and Symbolic Manipulation

You can use a user-defined function as an argument for the
TI-89 / TI-92 Plus’s built-in algebra and calculus functions.

For Information about Creating a User-Defined Function

Undefined Functions

Tip: To select d from the
Calc
toolbar menu, press
1
(or press
keyboard).
2 =
on the

Single-Statement Functions

Tip: To select limit from the
Calc
toolbar menu, press
3
.
Tip: To select ‰ from the
Calc
toolbar menu, press
2
(or press
keyboard). To select taylor,
9.
press
2 <
on the
Refer to:
¦ “Creating and Evaluating User-Defined Functions” in Chapter 5.
¦ “Graphing a Function Defined on the Home Screen” and
“Graphing a Piecewise Defined Function” in Chapter 12.
¦
“Overview of Entering a Function” in Chapter 17.
You can use functions such as
f(x), g(t), r(q)
assigned a definition. These “undefined” functions yield symbolic results. For example:
Use and
DelVar
g(x)
to ensure that
are not defined.
f(x)
Then find the derivative of
f(x)ùg(x)
with respect to x.
You can use user-defined functions consisting of a single expression. For example:
§
¦ Use
sec(x) =
Then find the limit of as x approaches
¦ Use
h(x)=
to create a user-defined secant function, where:
1
cos(x)
sec(x)
/4
.
p
to create a user-defined function
Define
x
sin(t) / t
0
Then find a 5th order Taylor
h(x)
polynomial for respect to
with
x
.
, etc., that have not been
h(x)
, where:
Define h(x)= ‰(sin(t)/t,t,0,x).
Chapter 3: Symbolic Manipulation 77

Multi-Statement vs. Single-Statement Functions

Multi-statement user-defined functions should be used as an argument for numeric functions (such as
nDeriv
and
nInt
) only.
In some cases, you may be able to create an equivalent single­statement function. For example, consider a piecewise function with two pieces.
When: Use expression:
x < 0 x ‚ 0 5 cos(x)
x
ë
Tip: You can use your computer keyboard to type lengthy text and then use
TI-GRAPH LINK to
the
TI-89 / TI 92-Plus.
Chapter 18 for more information.
Tip: To select
Calc
toolbar menu, press
B:nInt.
Tip: To select ‰ from the
Calc
toolbar menu, press
2
(or press
keyboard).
nInt
2 <
send it to
See
from the
on the
¦
If you were to create a multi-statement user-defined function with the form:
Func If x<0 Then Return ëx Else Return 5cos(x) EndIf EndFunc
Define y1(x)=Func:If x<0 Then: ... :EndFunc
Then numerically
y1(x)
when
with
x
.
Define y1(x)=when(x<0,ëx, 5cos(x))
integrate respect to
¦
Create an equivalent single-statement user-defined function.
Use the
TI-89 / TI-92 Plus’s
built-in function.
Then integrate
y1(x)
with respect to x.
Press ¥ ¸ for a floating-point result.
78 Chapter 3: Symbolic Manipulation

If You Get an Out-of-Memory Error

The TI
89 / TI-92 Plus stores intermediate results in memory and
-
then deletes them when the calculation is complete. Depending on the complexity of the calculation, the TI out of memory before a result can be calculated.
89 / TI-92 Plus may run
-

Freeing Up Memory

Simplifying Problems

¦ Delete unneeded variables and/or Flash applications, particularly
large-sized ones.
Use
as described in Chapter 21 to view and
delete variables and/or Flash applications.
¦ On the Home screen:
ƒ
Clear the history area (
You can also use
ƒ
8
) or delete unneeded history pairs.
9
to reduce the number of history pairs
that will be saved.
3
¦ Use
a large number of digits, this uses less memory than
Exact/Approx = APPROXIMATE
to set
. (For results that have
AUTO
or
EXACT
For results that have only a few digits, this uses more memory.)
¦ Split the problem into parts.
Split
solve
(aùb=0,var
)
into
solve
Solve each part and combine the results.
(a=0,var
)
and
solve
(b=0,var
)
¦ If several undefined variables occur only in a certain
combination, replace that combination with a single variable.
m
If
and c occur only as
In the expression
cñ+ c
ñ
use
. In the solution, replace c with
1 ìc
ñ
mùc
, substitute e for
ñ
(a+b)ñ+ (a+b)
1 ì(a+b)
ñ
mùc
ñ
, substitute c for
(a+b)
ñ
.
.
(a+b)
and
¦ For expressions combined over a common denominator, replace
sums in denominators with unique new undefined variables.
In the expression
añ+bñ + c añ+bñ + c
and use
.
x
añ+bñ + c
y
x
+
. In the solution, replace d with
d
d
+
y
añ+bñ + c
, substitute d for
.
.
¦ Substitute known numeric values for undefined variables at an
earlier stage, particularly if they are simple integers or fractions.
¦ Reformulate a problem to avoid fractional powers.
¦ Omit relatively small terms to find an approximation.
Chapter 3: Symbolic Manipulation 79

Special Constants Used in Symbolic Manipulation

The result of a calculation may include one of the special constants described in this section. In some cases, you may also need to enter a constant as part of your entry.
x=x is true for any value of x.

true, false

These indicate the result of an identity or a Boolean expression.
5<3 is false.
n1 ... @n255
@
For @, press:
¥§
TI.89
:
,
e
¥ *
:
¥ s
2
:
2
2
TI.92 Plus
ˆ
For ˆ, press:
TI.89 TI.92 Plus:
For e, press:
TI.89: TI.92 Plus:

undef

This notation indicates an “arbitrary integer”
A solution is at every integer multiple of p.
that represents any integer.
When an arbitrary
R
integer occurs multiple times in the same session, each occurrence is numbered consecutively. After it
Both @n1 and @n2 represent any arbitrary integer, but this notation identifies separate arbitrary integers.
reaches 255, arbitrary integer consecutive numbering restarts at @n0. Use
2:NewProb @n1
Clean Up
to reset to
.
ˆ represents infinity,
and e represents the constant
*
(base of the natural logarithms).
These constants are
s
often used in entries as well as results.
This indicates that the result is undefined.
2.71828...
Mathematically undefined
(undetermined sign)
„ˆ
Non-unique limit
80 Chapter 3: Symbolic Manipulation

Chapter 4: Constants and Measurement Units

Preview of Constants and Measurement Units.................................... 82
Entering Constants or Units ................................................................... 83
Converting from One Unit to Another................................................... 85
4
Note: Constant and unit names always begin with an underscore
_
.
Setting the Default Units for Displayed Results .................................. 87
Creating Your Own User-Defined Units................................................ 88
List of Pre-Defined Constants and Units............................................... 89
UNITS
The units from different categories.
Page 3
systems of measurement to specify the default units for displayed results.
dialog box lets you select the available constants or
This category lists
constant values.
Remaining categories
list available units.
(
) of the
MODE
dialog box lets you select from three
Note: You can also use
getUnits()
default units or set the default units. Refer to Appendix A.
to get a list of the
setUnits()
International system of measurements (metric or
to
By using the unit features, you can:
MKS) – meters, kilograms, etc.
English system – feet, pounds, etc.
Lets you select the units you want to use.
¦ Enter a unit for values in an expression, such as 6_m
23_m/_s ù10_s. The result is displayed in the selected default units.
¦ Convert values from one unit to another within the same
category.
¦
Create your own user-defined units. These can be a combination of existing units or unique “standalone” units.
Chapter 4: Constants and Measurement Units 81
ù
4_m or

Preview of Constants and Measurement Units

Using the equation f = mùa, calculate the force when m = 5 kilograms and a = 20 meters/secondñ. What is the force when a = 9.8 meters/secondñ. (This is the acceleration due to gravity, which is a constant named _g). Convert the result from newtons to kilograms of force.
Steps
1. Display the
Page 3
select
MODE
dialog box,
Unit System
. For
SI
for the metric system of
mode,
measurements.
Results are displayed according to
these default units.
2.
The UNITS dialog box lets you select
Now, instead of re-entering
Also, you can now use the UNITS
an acceleration unit for
Create
meters/second
units from an alphabetical list of categories. You can use
to scroll one page at a time
2C
through the categories.
each time you need it, you can use
_ms2
.
dialog box to select
Acceleration
2
named _ms2.
_ms2
category.
2D
_m/_s
from the
and
ñ
3. Calculate the force when m = 5 kilograms (_kg) and a = 20 meters/second
If you know the abbreviation for a
unit, you can type it from the keyboard.
2
(_ms2).
4. Using the same m, calculate the force for an acceleration due to gravity (the constant _g).
For _g, you can use the pre-defined
constant available from the UNITS dialog box or you can type
_g
.
³
TI-89
Keystrokes
3…B
1
¸
29DB ¸ e29 DDDB
S
¸ Z2§ ¥ 2™
MS
j2¸
5
¥ 2™ jp
KG
20
¥2™
MSj2
¸
5
¥ 2™
KG
jp 29B
G
j ¸¸
TI-92 Plus
Keystrokes Display
1
B
3… ¸
M
¥
9
DB
M
¸ e¥9
DDDB
S
¸ Z2§
2
MS 2
¸
5
2
KG
20
p
2
MS2
¸
5
2
KG
p
¥
B
9
G
¸¸
If you use the UNITS dialog box to select a unit, the _ is entered automatically.
5. Convert to kilograms of force (_kgf).
displays the 4 conversion
2
operator.
B2¥ 2™ j¸
82 Chapter 4: Constants and Measurement Units
KGF
B
22
KGF
¸

Entering Constants or Units

You can use a menu to select from a list of available constants and units, or you can type them directly from the keyboard.

From a Menu

2D
and
2C
Tip: Use to scroll one page at a time through the categories.
Note: If you created a user­defined unit for an existing category (page 88), it is listed in the menu.

From the Keyboard

Note: You can type units in
either uppercase or lowercase characters.
The following shows how to select a unit, but you can use the same general procedure to select a constant.
From the Home screen:
1. Type the value or expression.
2. Display the
UNITS
dialog box.
6.3
Press:
2 À
TI.89: TI.92 Plus:
¥ 9
3. Use D and C to move the cursor to the applicable category.
4. To select the highlighted (default) unit, press
¸
. – or – To select a different unit from the category, press B. Then highlight the applicable unit, and press
¸
.
You can also move the
cursor by typing the first
letter of a unit.
The selected unit is placed in the entry line. Constant and unit names always begin with an underscore (
If you know the abbreviation that the
6.3_pF
_
).
TI-89 / TI-92 Plus
uses for a particular constant or unit (refer to the list that begins on page 89), you can type it directly from the keyboard. For example:
256_m
The first character must be an underscore ( _ ). For _, press:
TI.89: TI.92 Plus:
¦
A space or a multiplication symbol ( optional. For example,
¥
2
256_m, 256 _m
ù
) before the underscore is
256ù_m
, and
are
equivalent.
However, if you are adding units to a variable, you must put a
space or ùbefore the underscore. For example,
x
as a variable, not as
with a unit.
x_m
is treated
Chapter 4: Constants and Measurement Units 83
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