HP 38g User Manual

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User's Guide

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aplet views

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SKETCH

aplet library -_____

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1 1 MODES ASIN

ACOS ATAN

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BIE^

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1 1

CHARS EEX

ABS

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1 ANSW R

for entering

a a

^0

a...z LIST

)

LOG

Alpha shift

7

■ 8

■

g

■

/

shift key

MATRIX [

___ ]_

10^

5

■ 6 ■ ^

(turquoise)

CLEAR NOTEPAD SPACE K

LN

1

■ 2 I 3

U

OFF PROGRAM

021 ■■ I

CANCEL

Key Conventions-Examples:

The {{OK}} menu-key label (when present in the display) acts the same as the | ENTER] key.

■ [ANSWER] Means press the shift key followed by the | ENTER] key.

|A...Z|A Means press the Alpha-shift key followed by the | HOME | key.

HP 38G Graphing Calculator

User’s Guide

HEWLETT®

PACKARD

HP Part No. FI 200-90013

Printed in Singapore

Notice

This manual and any examples contained herein are provided “as is” and are subject to change without notice. Hewlett-Packard Company makes no warranty of any kind with regard to this manual, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hewlett-Packard Co. shall not be liable for any eiTors or for incidental or consequential damages in connection with the furnishing, performance, or use of this manual or the examples herein.

© Copyright Hewlett-Packard Company 1995. All rights reserved. Reproduction, adaptation, or translation of this manual is prohibited without prior written permission of Hewlett-Packard Company, except as allowed under the copyright laws.

The programs that control this product are copyrighted and all rights are reserved. Reproduction, adaptation, or translation of those programs without prior written permission of Hewlett-Packard Co. is also prohibited.

Hewlett-Packard Co.

Australian Calculator Operation

347, Burwood Highway

Burwood East

Victoria 3151

Australia

Acknowledgments

Hewlett-Packard gratefully acknowledges the members of the Education Advisory Committee (Walter Bitz, Tom Dick, Mark Howell, Alice Kaseberg, Jim McManus, Carla Randall, Alison Warr, and Wade White) for their assistance in the development of this product.

Edition History

Edition 2............... .January 1998

Contents

Getting Started

Starting Out...........................................................................	1-1
The Keyboard........................................................................	1-2
The Display.............................................................................	1-6
Display Modes....................................................................	1-7
Using Input Forms.............................................................	1-8
Home History......................................................................	1-9
Menu Lists........................................................................	1-10
Aplets and Their Views.......................................................	1-11
Aplets.................................................................................	1-11
Views..................................................................................	1-12
Exploring an Aplet View by View...................................	1 -14
Catalogs and Editors...........................................................	1-16
Storing and Recalling Variables........................................	1-17
Notes and Sketches..............................................................	1-18
Note View and Sketch View............................................	1-18
The Notepad......................................................................	1-23
Managing Aplets....................................................................	1 -25
Sending and Receiving Aplets............................................	1-27

Mathematical Calculations

How to Do Calculations........................................................	2-1
Entering Expressions.........................................................	2-1
Complex Numbers..............................................................	2-4
Clearing Numbers..............................................................	2-4
Using Previous Results.......................................................	2-4
Storing in Variables...............................................................	2-6
The VAR Menu......................................................................	2-7
Symbolic Calculations.........................................................	2-10
Using Math Functions.........................................................	2-12
The MATH Menu.............................................................	2-12
The Math Functions by Category...................................	2-13

Contents-1

Plotting and Exploring Functions

Defining a Problem...............................................................	3-1
Select an Aplet....................................................................	3-2
Define an Expression (Symbolic View)............................	3-2
Evaluating Expressions.....................................................	3-5
Examples: Defining Expressions......................................	3-6
Plotting....................................................................................	3-7
Plot the Expression (Plot View)........................................	3-7
Examples: Plotting.............................................................	3-8
Exploring the Plot...............................................................	3-11
Tracing..............................................................................	3-12
Zooming.............................................................................	3-13
Other Views for Scaling and Splitting the Graph..........	3-16
Setting Up the Plot (Plot Setup).........................................	3-18
Interactive Root-Finding.................................................	3-19
Examples: Root-Finding with Plots...............................	3-21
Using a Table of Numbers..................................................	3-23
Display a Table of Numbers (Numeric View)...............	3-23
Exploring the Table of Numbers....................................	3-24
Setting Up the Table (Numeric Setup)...........................	3-25
Building Your Own Table of Numbers..........................	3-26
More Examples....................................................................	3-28

Solve

Solving Equations..................................................................	4-2
Define the Equation...........................................................	4-2
Solve for the Unknown Variable......................................	4-4
Plotting the Equation............................................................	4-6
Interpreting Results...............................................................	4-7
Plotting to Find Guesses........................................................	4-8
About Variables...................................................................	4-11

Contents-2

Statistics

Example: Finding a Linear Equation to Fit Data	..............5-2
Entering Statistical Data.......................................................	5-5
One-Variable Data.............................................................	5-6
Two-Variable Data.............................................................	5-9
Managing Statistical Data...............................................	5-12
Analyzing the Data..............................................................	5-14
Defining a Regression Model (2VAR)............................	5-14
Computing Statistics (IVAR and 2VAR)....................	5-16
Plotting..................................................................................	5-19
Plot Types..........................................................................	5-20
Fitting a Curve to 2VAR Data........................................	5-21
Regression Coefficients...................................................	5-21
Plot Settings......................................................................	5-22
Trouble-shooting..............................................................	5-22
Exploring the Plot................................................................	5-23
Calculating Predicted Values..........................................	5-24

Using Matrices

Creating and Storing Matrices............................................	6-1
Matrix Arithmetic..................................................................	6-6
Solving Systems of Linear Equations...............................	6-8
Matrix Functions....................................................................	6-9
Examples...........................................................................	6-13

Using Lists

Creating and Storing Lists...................................................	7-1
List Functions.........................................................................	7-4
Finding Statistical Values for List Elements...................	7-7

Contents-3

Programming

The Contents of a Program...............................................	8-1
Structured Programming.................................................	8-1
Using the Program Catalog..................................................	8-1
Programming Commands....................................................	8-9
Aplet Commands..............................................................	8-10
Branch Commands..........................................................	8-11
Drawing Commands........................................................	8-13
Graphic Commands.........................................................	8-15
Loop Commands..............................................................	8-17
Matrix Commands...........................................................	8-18
Print Commands..............................................................	8-20
Prompt Commands.........................................................	8-21
Stat-One and Stat-two Commands.................................	8-25
Storing and Retrieving Variables in Programs................	8-26
The Variable Menu..........................................................	8-26
Plot-View Variables.........................................................	8-28
Symbolic-View Variables................................................	8-35
Numeric-View Variables.................................................	8-37
Note Variables..................................................................	8-39
Sketch Variables...............................................................	8-39
Menu Maps of the VAR menu.............................................	840
Home Variables................................................................	8-40
Function Variables...........................................................	8-40
Parametric Variables......................................................	8-41
Polar Vciriables................................................................	8-41
Sequence Variables............................................................	842
Solve Variables...................................................................	842
Statistics Variables............................................................	843

Reference Information

Regulatory Information........................................................	9-1
Limited One-Year Warranty...............................................	9-3
Service......................................................................................	94
Batteries..................................................................................	9-7
Resetting the HP 38G............................................................	9-8
Memory Specifications..........................................................	9-8
Glossary..................................................................................	9-9
Selected Status Messages....................................................	9-11

Content84

Getting Started

Read this chapter first! It will get you started using your

HP 38G, from turning it on to running aplets.

Starting Out

The Cover The protective cover swivels to provide a base for the

calculator. Be sure to protect the display by replacing the cover before transporting the calculator. Slide the cover gently so as not to hit the keys.

First push the
cover away	Then swivel the cover to the
from you until it
catches.	back and slide it towards you.

ON/CANCEL When the calculator is on, the |ON| key cancels the current operation.

OFF	Pressing ■ I ON I (that is, ■ [OFF]) turns the calculator off.

Getting Started 1-1

Demo	To see a demonstration of the HP 38G's features, type DEMO
	into the edit line in Home. (Press | HOME | |A...Z|D |A...Z|E
	|A...z|M |A...z|0 I ENTER|.) To Stop the demo, press any key.
Home	Home is the calculator’s home base. If you want to do
	calculations, or you want to quit the current activity (such as
	an aplet, a program, or an editor), press | HOME |.
Power	To save power, the calculator turns itself off after several
	minutes of inactivity. All stored and displayed information are
	saved.
	If you see the ((*)) annunciator or the Low Bat message,
	then the calculator needs fresh batteries. See chapter 9.

The Keyboard

Shifted The ■ (shift) key is a shifted keystroke that accesses the

Keystrokes operation printed in turquoise above a key. For instance, to

®access the Modes screen, press ■, then | HOME |. (You do not need to hold down the ■ .) This is depicted in this manual as “press ■[MODES] ."

To cancel a shift, press ■ again.

Alpha Shift	The alphabetic keys are also	shifted	keystrokes. For instance,
l^ -^l	to type z, press | A...Z | (T|. (The letters are printed in light
	green to the lower right of each key.)
	To cancel Alpha, press | A...	Z | again.
	• For a lowercase letter, press ■ | A...		Z |.
	• For a string of letters, hold down | A...Z | while typing.

1-2 Getting Started

Menu Keys You can press fuBl to see this screen;

			Parametric
			Polar
			Sequence
	menu labels		Solve
			mm
	menu keys
	« The top-row keys are called menu keys because their
	meanings depend on the context—that’s why their tops
	are blank.
	• The bottom line of the display shows the labels for the
	menu keys’ current meanings, {{SAVE}} is the label for the
	first menu key in this picture. “Press {{SAVE}}’’ means to
	press the leftmost top-row key.
Math Keys	Home (press | HOME |) is the place to do calculations.
	• Keyboard keys. The most common arithmetic operations
	are on the keyboard, such as the arithmetic (like (T)) and
	trigonometric (like |SIN|) functions. Press | ENTER | to
	complete the operation : |^] 256 | ENTER | displays 16 .
			P256
			16

Getting Started 1-3

MATH menu. The | MATH | menu is a comprehensive menu list of math operations that do not appear on the keyboard. It also includes categories for all other functions and programmable commands. The functions are grouped by category, ranging in alphabetical order from Calculus to Trigonometry.

		CEILING
	Re.3l C
	Stat-Tyo	DEG+RFID
	Symbolic	FLOOR
—	Tests ?	FNROOT »
BDBSISiaiSI		iHamBM

The arrow keys scroll through the list (Q. ®) ^^d move from the category list to the item list (0, Q).

Press {{CANCL}} to cancel the MATH menu.

Pressing {{CMDS}} displays the list of Program Commands. Pressing {{CONS}} displays the list of Program Constants. Pressing {{MTH}} displays the list of Math Functions.

1-4 Getting Started

Keys for Entry and Editing

Key	Meanine
	Pressing |ON| while the calculator is on
(CANCEL)	cancels the current operation. Pressing ■
	first turns the calculator off.
■ (shift)	Accesses the function printed in turquoise
	color above a key.
1 HOME 1	Home base for calculations.

[M]Alphabetic entry—press before a letter key.

1 ENTER 1 Enters an input or executes an operation. In calculations, 1 ENTER 1 acts like “=“ When

{{OK}} is present as a menu key, | ENTER] acts the same as {{OK}}.

QStarts a negative number. To enter -5, press 5.

[EEX]	Enters an exponent of 10. To enter 5x10^
	you press 5 ■ [EEX] 9. This appears as
	5E9 or, after pressing | ENTER],
	5000000000.
1 x,T,e 1	Independent variable key. Types X, T, 0, or
	N into the display, depending on the
[MD	current context.
	line.
	Delete key. Backspaces if at the end of the
■ [CLEAR]	Clear key. Clears all data on the screen
	except settings, which return to their default
	values.
0 B 0	Cursor-movement (navigation) keys. Press
	■ first to move far.
a
■ [CHARS]	Displays all available characters. To type
	one, highlight it and press {{OK}}.

Inactive Keys If you press a key that does not operate in the current context, a warning symbol like this A appears. There is no beep.

Getting Started 1-5

The Display

To adjust the	Simultaneously press			and 0 (or0) to increase (or
contrast	decrease) the contrast
The Parts of
the Display	history	6*3		18
		8/5
	edit line :			1.6
		17894			_ menu-key
Annunciators					labels
	BMmsm		Shift in effect for next keystroke. To cancel,
			press ■ again.
	a		Alpha in effect for next keystroke. To cancel,
			press 1 A...Z 1 again.
	((•))		Low battery power. See chapter 9.
	i		Busy.
			Data is being transferred via infrared or cable.
	A T		There is more history in the Home display.
			Scroll up or down to see it.
	RAD		Radians angle mode is set for Home.
	GRD		Grads angle mode is set for Home.
	DEG
			Degrees angle mode is set for Home.
To clear the
	• Press		to clear the edit line.
display

•Press ■ [CLEAR] to clear the edit line and the display history.

1-6 Getting Started

Display Modes

You can set the Home modes in ^ [MODES]. You make your selections using an input form. To fill out an input form, see “Using Input Forms,” after this table. The Decimal Mark setting affects all aplets, as well as Home.

When you are done setting MODES, press | HOME | to return to the Home screen.

[MODES] Setting

Angle

Measure

Number

Format

Decimal

Mark

Title

Options

Angle values are:

Degrees. 360 degrees in a circle.

Radians. 2Tr radians in a circle.

Grads. 400 grads in a circle.

Standard. Full-precision display.

Fbted. Displays results rounded to a number of decimal places. Example ; 123.456789 becomes 123.4568 in Fixed 4 format.

Scientific. Displays result with an exponent, one digit to the left of the decimal point, and the specified number of decimal places.

Example: 123.456789 becomes 1.23E2 in Scientific 2 format.

Engineering. Displays result with an exponent that is a multiple of 3, and the specified number of significant digits beyond the first one.

Example: 123.456E7 becomes 1.23E9 in Engineering 2 format.

Fraction. Displays results as fractions based on the specified number of decimal places for precision. Examples: 123.456789 becomes 123 in Fraction 2 format, and .333 becomes 1/3 and 29/1000 becomes 2/69.

Dot or Comma. Displays a number as 12456.98 (Dot mode) or as 12456,98 (Comma mode).

Dot mode uses commas to separate elements in lists and matrices, and to separate function arguments. Comma mode uses periods as separators in these contexts.

Customizes the title in the Home screen.

Getting Started 1-7

To display fractions

To convert a result to a fraction

Set Fraction mode to display future results as fractions,

1.Press ■ [MODES], then press 0 to select NUMBER

FORMAT.

2.Press {{CHOOS}}, highlight Fraction, and press {{OK}}.

3.Press and enter a number for the precision of the fraction. The precision number determines how many digits appear in the denominator. Press | ENTER |.

4.Press I HOME I to display Home.

1.Set Fraction mode (as in the previous procedure).

2.In Home, press 0 to highlight the number in the history display that you want to convert.

3.Press ((COPY)) lENTERj.

Using Input Forms

An input form shows several fields of information for you to examine and specify. After highlighting the field to edit, you can enter or edit a number (or expression). You can also select options from a list ({{CHOOS}}). Some input forms include items to check ({{/CHK}}).

HOME MOPES I

ANGLE MEASURE: [^PfiifeEH

NUMRER FORMAT; Standard

DECIMAL MARK; Dot < . >

TITLE; HOME

CHOOSE ANGLE MEASURE

Example: Change the Angle Measure.

Setting Modes

1.Press ■ {MODES} to open the MODES input form.

2.The cursor (highlight) should be on the first line, ANGLE MEASURE. Press {{CHOOS}} to display a list of choices. Highlight Degrees, Radians, or Grads and press

{{OK}}.

3.When done, press | HOME | to return to Home.

1-8 Getting Started

H i n t	Whenever an input form has a list of choices for a field,
	you can press (T) to cycle through them instead of using
	{{CHOOS}}.

To reset values To reset the original, default value in an input form, press

I DEL |. To reset all values in the form, press ■ [CLEAR].

Home History

The Home display (press | HOME |) shows up to four lines of history : the most recent input and output. Older lines scroll off the top of the display but are retained in memory; press m to view them. Note that these examples are in Standard display mode.

	input	—	HDME
				-result
	last input-		T 2
			1.41421356237	■last
	edit	— 5*77+4		result
	line

When you highlight a previous input or result (pressing [Tl) the {{COPY}} and {{SHOW}} menu labels appear. Pressing

{{COPY}} copies the highlighted value to the edit line.

HOME

T 2

1.41421356

5*77+1.414213562374

To copy a Highlight the line (press |T|) and press {{COPY}}. The number previous line (or expression) is copied into the edit line.

To repeat a To repeat the very last line, just press ( ENTER |. Otherwise, previous line highlight the line (press |T1) first, and then press | ENTER). The

highlighted expression or number is re-entered.

Getting Started 1-9

To re-use a Press ■ [ANSWER] (last answer) to put the last result from previous result Home into an expression. Ans is a variable that is updated

each time you press [ ENTER |.

Example	See how [ANSWER] retrieves and reuses the last result (50),
	and I ENTER I updates Ans (from 50 to 75 to 100).
	50 I ENTER I
		50
	25QH [ANSWER]	25+flns
	1 ENTER! I ENTER!	75
		100

You can use the last result as the first expression in the edit line without pressing ■ [ANSWER]. Pressing 0, 0, or

[7], (or other operators that require a preceding argument) automatically enters Ans before the operator.

You can reuse any other expression or value in the Home display by highlighting the expression (using the arrow keys), then pressing {{copy}}.

To display the	If a number or expression is too long to appear on one line,
full number	then highlight it (press 0) and press {{SHOW}}. If it is still too
	long, press [0 to see more. When done, press {{OK}}.

Menu Lists

A menu offers you a choice of items. The menu labels across the bottom of some displays are one kind of menu. A menu list, which appears in one or two columns, is another kind.

		FUNCTIONS
Plot-Table	Stat-Two		CEILIHG
Overlay Plot			DEG-»RflD
fiuto Scale	Symbolic		FLOOR
Decimal	Tests V		FNROOT w

•The ▼ arrow in the display means more items below.

•The A arrow in the display means more items above.

1-10 Getting Started

To search a menu list

To cancel a menu list

®Press @ or 0 to scroll through the list. If you press

■Q or ■ [^, you’ll go all the way to the end or the beginning of the list. Highlight the item you want to select, then press {{OK}} (or | ENTER |).

•If there are two columns, the left column shows general categories and the right column shows specific contents. Highlight the category on the left, then highlight the item on the right. The list on the right changes when a different category is highlighted. Press {{OK}} or [ ENTER |.

•To speed-search a list, type the first letter of the word. For example, to find the Matrix category in |MATH|, press M

(the g key).

•To go up a page, you can press ■ Q- To go down a page,

press ■

.

Press CANCEL or {{CANCL}}. This cancels the current operation.

Aplets and Their Views

Aplets

Function

Parametric

Polar

The HP 38G provides built-in applications to solve specific kinds of math problems. These little applications, or aplets, are accessed from the Library (|LIB|).

The library lists (and manages) all the aplets in the calculator, whether they came with the calculator or were added later.

There are six types of math aplets built into the HP 38G :

•Real-valued, rectangular function y in terms of x. Example: y = 2X-E3.

•Parametric functions x and y in terms of t. Example: x = cos(0 and y = sin(f).

•Polar function r in terms of an angle 8.

Example: r = 2cos(40 ).

Getting Started 1-11

Sequence

Solve

Statistics

Views

SYMB

PLOT

INUM!

®Sequence function i/in terms of n, or in terms of previous terms in the sequence, such asUn~i and Example:

i/i = 0, f/2 = l,and a = +

® Finding the roots of an equation.

Example: x + 1 = -x-2.

e Analysis of one-variable (x) or two-variable (x and y) statistical data.

An aplet is represented in different ways. These views compose an aplet problem and its solution. Here are illustrations of three major and six supporting aplet views.

Symbolic view. The defining equation(s) (in most aplets). The equation contains a symbolic expression.

Plot view. The graph of the function(s).

FUNCTION SVMtDLIC

^F10f>SIH<X)
F3<:x)=
F4<X>=
F5<X>=	¥

		K: 0 FICH		: <! I8H:IH
Numeric view.	Sampled		FI
			.0ЦЦBЗЭH
values of the function(s).
			.SRSSSOS
		0	.H7RH353
		BHoai

1-12 Getting Started

■[SETUPSYMB]

■[SETUPPLOT]

■[SETUP-

NUM]

Symbolic Setup (■ |SYMB|).

Sets parameters for the symbolic expression.

Plot Setup (■ I PLOT I). Sets parameters to plot a graph.

FUMCTIDN SVMeOUC SETUP

ANGLE MEASURE:Radian

CHMSE ANGLE MEASURE

^^^FONCIiDN	PLDT
KRNG: IMÜJiii	■ 6.5
VRNG; -3. 1	3.2
KTICK! 1	TTICK: 1
RES: Faster

ENTER MINIMUM HDRIZDNTAL VALUE

Numeric Setup (■ | NUMQ.	^^PUHCTIUN NUMERIC SETUP
	NUMSTART: ISHPBMBI				lga
Sets parameters for building	NUMSTEP:		. 1
a table of numeric values.	NUMivPE: fiutomatic
	NUMSBUM: 4

ENTER STARTING VALUE FUR TAiLE

■ [VIEWS]	Split Screen view. Two
Plot-Table
	views side by side.
I [NOTE]	Note view. Text to
	supplement an aplet.
I [SKETCH]	Sketch view. Pictures to
	supplement an aplet.
	BannaHQi	BrjfaiinM
Changing	Each view is a separate “environment." To change the view,
Views	press another view key. To change to Home, press | HOME |.
	You do not explicitly “close” the current view, you just enter

another one-like passing from one room into another in a house.

Getting Started 1-13

Canceling	To cancel an operation within a view, press | O N | (the
Operations	CANCEL key). Pressing CANCEL will cancel pending
	operations, but will not change the view.

Exploring an Aplet View by View

Example	Use the Function aplet to explore the real function
	y = sin(l/x)
	using the Symbolic, Plot, and Numeric views. All the
	information you enter is automatically saved

1.Open the Function aplet. Press

|LIB|. If necessary, press 0 to highlight Function.

Then press {{START}} to display the Symbolic view.

2.Enter the expression.

(If necessary, highlight a new line or press I DEL I to clear the highlighted expression.)

Press 1 0 {{X}} {EÑTERI

3.There are three Setup views. They are the shifted keystrokes for |SYMB|,

I PLOT I, and |NUM|. Check that

Radians are set for Symbolic Setup; Press ■ [SETUP-SYMB] and choose Radians, if necessary.

4.Plot the graph. Press | PLOT |. The coordinates show that when .»=0, KJK) is undefined.

(If your plot does not look like this, try resetting the default plot settings; Press ■ [SETUP-PLOT]

■ [CLEAR].)

	Function
	Parametric
	Polar
	Sequence						w
	Solye
		FUNCTION SVM6DÜC
		v<'FKH)=siHa^K>
		F200 =
		F3(X)=
		F4<X)=
		F5<H)=					w
		FUNCTION SYMBOLIC SETUP
	ANGLE MEASURE:				Radian

CHOOSE ANGLE MEASURE

............................	t
K; 0 FKK	: UNDEFINED IBiann

1-14 Getting Started

5. Trace the plot. Move the crosshairs along the plot by pressing 0] and

B-

6.Zoom in and zoom out. Press {{MENU}} {{ZOOM}}, highlight In 4 X 4 , and press {{OK}}.

To restore the original scale, select {{ZOOM}} Un-zoom.

7.Display the numbers. To display a table of data, press |NUM|. YOU see the independent (X) and dependent (FI) variables listed with sampled values.

(If your table does not look like this, try resetting the default numeric settings : Press ■ [SETUP-NUM]

■[CLEAR}.)

8.Split the screen. Press ■ [VIEWS], then select Plot-Table {{OK}} to display these two views simultaneously.

Press I PLOT I to view the full-screen plot again.

............................ /	.... ,..
	i ' ' ' ' ' '
K:1.3 FKK	i; .sissBas

K FI

-.60H3B -.HH?S3 -.HOSES -.SEBBH -.g03I3

s. HOSES	.SEBB35
I.60H3P5	.HH?535

Getting Started 1-15

Automatic With this example you have defined a new aplet-an aplet

Saving containing data for the solution of y = sin(l/x). The data are automatically saved in the Function aplet. If you want to create another aplet based on Function, then you can give this one a new name in the Library ({{SAVE}}).

To keep as much memory available for storage as possible, delete aplets you no longer need.

Annotating The Note view (■ [NOTE}) attaches a note to the current with Notes aplet. See “Notes and Sketches" later in this chapter.

Annotating The Sketch view (■ [SKETCH]) attaches a picture to the

with Sketches current aplet. See “Notes and Sketches” later in this chapter.

Calculating in You can do calculations in aplets wherever you can enter Aplets numbers or expressions. Use the math keys on the keyboard

or use operations from the | MATH | menu list. Chapter 2 discusses math calculations.

Catalogs and Editors

The HP 38G has several catalogs and editors. They access features and stored values (numbers or text or other items) that are not part of aplets. A catalog lists items, which you can delete or transmit. An editor lets you create or modify items and numbers.

Catalogs/Editors

Cataloe/Editor	Contents
Library ((051)	Aplets.
List (■ [UST])	Lists. In Home, lists are enclosed in {].
Matrix	Oneand two-dimensional arrays. In
(■ [MATRIX])	Home, arrays are enclosed in [ ].
Notepad	Notes (short text entries).
(■ [NOTEPAD])
Program	Programs created by a user.
(■ [PROGRAM])

1-16 Getting Started

ENTER].

Storing £uid Recalling Variables

To store a number

Variables are storage locations for numbers or values. The

HP 38G has different categories of variables for different kinds of data. The names for the variables are predefined. For real numbers, there are 27 variable names available, A through Z and 0. (Other categories and their names are in chapter 2.)

A variable holds just one value, so if you store a new number in it, any previous number is lost.

You can store a number from Home’s edit line into a named variable with the {{STO^}} (store) menu key. ({{STO^}} appears on a menu-key label whenever it is possible to store a value.) For example.

75{{STO^)} [TZzIA	7 5^A4
ENTER	75

When you press | ENTER), the number 75 is stored into the variable named A.

To store the last answer, you don’t need to re-type the number:

To recall a number

{{STO>}} [AIZIB	Ans ►Bi
ENTER	75

This stores 75 (the last result) in B.

In Home, to recall a value from a stored variable back to the edit line, just type the name of the variable and press |

i A...Z IA [ENTER!

75

Getting Started 1-17

“Deleting”	A variable always has a value in it, even if that value is zero.
Variables	When you store another value into a variable, it overwrites the
	previous value. So you cannot delete a variable’s value, but
	you can overwrite it.
	The predefined variable names (such as A through Z) always
	exist; you cannot change or delete them.
Home and	Most variables are Home variables, which means they are
Aplet	shared throughout the different contexts of the calculator.
Variables	Some variables are aplet variables, which means they apply
	only to the current aplet. Aplet variables are data sets,
	expressions, and settings made within an aplet.

Notes and Sketches

The HP 38G has compact text and picture editors for entering

notes and sketches.

® The Notepad is an independent collection of notes.

* Each aplet includes a Note view and a Sketch view for that aplet only.

Note View and Sketch View

You can attach text to an aplet in its Note view (■ [NOTE]), or attach pictures to it in its Sketch view (■ [SKETCH]).

To write a note 1. In an aplet, press ■ [NOTE] for the Note view.

In Note view

2.Use the note editing keys shown below.

3.Set Alpha lock (([A...Z}}) for quick entry of letters. For lowercase Alpha lock, press ■ ((A...Z}}.

®To type a single letter of the opposite case, press

■letter.

4.Your work is automatically saved. When done, turn off Alpha lock (by pressing ([A...ZH]}) if you want to go to

Home. (Otherwise, the | HOME | key will still type A.)

1-18 Getting Started

	Note Editing	Key	Meaning
	Keys
		{{SPACE}}	Space key for text entry.
		{{APACE}}	Displays previous page of the note.
		{{PAGET}}	Displays next page of the note.
		{{A...Z}}	Alpha-lock for letter entry.
		■ {{A...Z}}	Lower-case Alpha-lock.
		{{BKSP}}	Backspaces cursor and deletes character.
		(HD	Deletes current character.
		1 ENTER!	Starts a new line.
		H {CLEAR]	Erases the entire note.
		1 VAR|	Menu for entering variable names, and
			contents of variables.
		1 MATH 1	Menu for entering math operations,
			program commands, and constant names.
		■ [CHARS]	Displays special characters. To type one,
			highlight it and press {{ECHO}}. Pressing
			{{OK}} copies the character and closes the
			CHARS screen.

To import a You can import a note from the Notepad into an aplet's Note note view, and vice-versa.

1.Open the destination note in the Notepad or in the Note view of an aplet.

2.Press I VAR|.

*If the source note is in the Notepad, press {{HOME}}, highlight Notepad in the left-hand list, then highlight the name of the source note in the right-hand list.

*If the source note is part of the current aplet, press

{{APLET}}, highlight Note in the left-hand list, then press 0 and highlight NoteText in the right-hand list.

3.Press {{VALUE}} {{OK}} to recall the contents of the source note into the destination note.

Getting Started 1-19

Sketch Keys	Key		Meanine
	{{STO^}}		Stores the specified portion of the
			current sketch to a graphics
			variable (G1 through GO).
	{{NEWP}}		Adds a new, blank page to the
			current sketch set.
	{{APACE}}		Displays previous sketch in the
			sketch set. Animates if held down.
	{{PAGET}}		Displays next sketch in the sketch
			set. Animates if held down.
	{{TEXT}}		Opens the edit line to type a text
			label.
	{{DRAW}}		Displays the menu-key labels for
			drawing (below).
	fPEH		Deletes the current sketch.
	■ [CLEAR]		Erases the entire sketch set.
	0		Turns off the menu-key labels. Press
			any menu key to restore them.
To draw a	1. In an aplet, press I	I[SKETCH] for the Sketch view.
sketch	2. Press {{DRAW}}.

3. Use the arrow keys to move the crosshairs (graphics cursor). To draw lines, boxes, or circles, use the menu keys (described next).

4. When done drawing, press {{OK}}. Your work is automatically saved. Press any other view key or | HOME | to exit the Sketch view.

1-20 Getting Started

To draw a line 1. In Sketch view, press {{DRAW}} and move the cursor to where you want to start the line

2.Press {{LINE}}. This turns on line-drawing.

3.Move the cursor in any direction to the end point for the line.

4.Press {{OK}} to finish the line.

To draw a box 1. In Sketch view, press {{DRAW}} and move the cursor to where you want any corner of the box to be.

2.Press {{BOX}}. This turns on box-drawing.

3.Move the cursor to mark the opposite corner for the box. You can adjust the size of the box by moving the cursor.

4.Press {{OK}} to finish the box.

To draw a	1. In Sketch view, press {{DRAW}} and move the cursor to
circle		where you want the center of the circle to be.
	2.	Press {{CIRCL}}. This turns on circle-drawing.
	3.	Move the cursor the distance of the radius.
	4.	Press {{OK}} to draw the circle.

Getting Started 1-21

DRAW Keys	Key	Meaning
	{{DOT-f}},	Dot on, dot off. Turns pixels on/off as crosshairs
	{{DOT-}}	move.
	{{LINE}}	Draws a line from the cursor’s starting position
		to the point at which you press {{OK}}. YOU can
		draw a line at any angle by moving the cursor.
	{{BOX}}	Draws a box from the cursor's starting position
		to the point at which you press {{OK}}.
	{{CIRCL}}	Draws a circle. The cursor’s starting position is
		the center of the circle. The cursor’s ending
		position (when you press {{OK}}) defines the
		radius.

To label parts 1. Press {{TEXT}} and type the text in the edit line. To lock

of a sketch	the Alpha shift on, press {{A...Z}} (for uppercase) or
	■ {{A...Z}} (for lowercase).
	2. To make the label a smaller character size, turn off
	{{BIG«}}. (Pressing {{BIG}} turns on {{BIGH}} and vice-
	versa.) The smaller character size cannot display
	lowercase letters.
	3. Press {{OK}}. Use the arrow keys to position the label where
	you want it.
	4. Press {{OK}} again to affix the label.
	5. Press {{DRAW}} to continue drawing, or press | HOME | to
	exit Sketch view.

To create a set You can create a sequence of up to ten sketches. This allows of sketches for simple animation.

«After making a sketch, press {{NEWP}} to add a new, blank page that will follow the current page. You can now make a new sketch. The new image becomes part of the current set of sketches.

®To view the next sketch in an existing set, press

{{PAGET}}. Hold {{PAGET}} down for animation.

®To remove the current page in the current sketch series, press [on |.

1-22 Getting Started