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Finance Application for the TI-89 / TI-92 Plus

Important Information 2 Where to Find Installation Instructions 3 The Time-Value-of-Money (TVM) Solver 4

Editing Values in the TVM Solver 5 Calculating TVM Outside of the TVM Solver 6

Finance Functions 7

Calculating Cash Flows 8 Calculating Amortization 9 Calculating Interest Conversion 9 Finding Days between Dates 10 Defining Payment Method 10

Finance Examples 11

Example 1 — Financing a Car 11 Example 2 — Calculating Interest on a Fixed Payment 12

Example 3: — Amortization 13 Error Messages 15 Error Recovery Instructions 16 Miscellaneous 17 How to Contact Customer Support 18

Finance Application for the TI-89 / TI-92 Plus 1

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Important Information

Texas Instruments makes no warranty, either expressed or implied, including but not limited to any implied warranties of merchantability and fitness for a particular purpose, regarding any programs or book materials and makes such materials available solely on an “as-is” basis.

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 product. Moreover, Texas Instruments shall not be liable for any claim of any kind whatsoever against the use of these materials by any other party.

Finance Application for the TI-89 à TI-92 Plus 2

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Where to Find Installation Instructions

For detailed instructions on installing this and other Flash applications, point your web browser to:

http://www.ti.com/calc/docs/guides.htm

Installing this application requires TI-GRAPH LINKé. To download a free copy of TI-GRAPH LINK for the TI-89 / TI-92 Plus, Point your web browser to:

http://www.ti.com/calc/docs/link.htm

Finance Application for the TI-89 / TI-92 Plus 3

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The Time-Value-of-Money (TVM) Solver

Use Time-Value-of-Money (

) functions to analyze financial instruments such as annuities,

TVM

loans, mortgages, leases, and savings.

The

TVM Solver

displays the time-value-of-money ( values, the

To access the variables outside the Finance folder. Note: Exit the variables. Otherwise, the variable currently highlighted by the cursor in the not display in the

screen automatically displays when you run the Finance application. It

TVM Solver

VAR-LINK

) variables:

TVM

solves for the fifth variable.

editor, press 2

TVM

TVM Solver

, and then press 2

variable list.

, æ, PV,

PMT, FV

. Given four variable

. They are located in the

to display the

TVM Solver

TVM

will

Press C and D to move the cursor between variables. After entering a new value, press D or

to save it. To solve for the unknown variable, press „

Note: The

VAR-LINK

Finance folder (where

variables are stored) is used by this

TVM

Compute

or ¥

application and previously-stored data can be overwritten without notification. Avoid using this folder for storing personal data.

TVM variables Default Definition Value Type

N0 I0

PV 0 PMT 0 FV 0 PpY 1 CpY 1 END

BEGIN

END

Number of payment periods real number

Annual interest rate (converted to a per-period rate based on the values of

PpY

and

CpY

)

real number

Present value real number

Payment amount real number

Future value real number

Payments per year integer > 0

Compounding periods per year integer > 0

Set annuity due (i.e. specify whether payment is

N/A

at the end or beginning of each period)

When you store a value to to the same value. To store a unique value to have stored a value to

does not change.

CpY

PpY

in the

PpY

TVM Solver

CpY

. If you store a value to

only, the value for

automatically changes

CpY

, you must store the value to

PpY

outside

the

TVM Solver

after you

CpY

, the value for

Note: Enter cash inflows as positive numbers, and cash outflows as negative numbers.

To solve for an unknown

1. Press

Finance Application for the TI-89 à TI-92 Plus 4

O ¸

TVM Solver.

Highlight press

Finance

to display the

with cursor and

variable, follow these steps.

TVM

Default (ƒ

TVM

8:Clear Editor

values.

)

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Enter the known values for

and FV. Press D or

save each new value.

N, I%

Enter a value for

PpY

, which automatically enters the same value for unique value for

Select

END

CpY

; if

PpY CpY

BEGIN

CpY

to specify the payment method by highlighting the option with the cursor and pressing

Place the cursor on the

TVM

variable for which you want to solve (i.e.

Press „

PMT

Compute

. The answer is computed and displayed and stored to the appropriate

variable. An

TVM

indicator calculator in the left column designates the solution variable.

, enter a

Editing Values in the TVM Solver

The following calculator editing keys are available in the TVM Solver. For more detailed explanation, see the TI-89 / TI-92 Plus Guidebook.

Cursors: C, D, A, and

Deletion options: 0, ¥ 0, ƒ

Insertion: 2

Clear options:

M, ƒ

The ƒ Toolbar

The ƒ Toolbar functions are exactly like the ƒ Toolbar on the TI-89 and TI-92 Plus on the Home screen. You can is placed on the calculator clipboard for use either within or outside the application. inserts the contents of the clipboard at the current cursor location (both within or outside the application).

4: Cut is not the same as 7: Delete. When you delete information, it is not placed in the

clipboard and cannot be retrieved.

7:Delete

8:Clear Editor

Cut, Copy, and Paste information within the TVM Solver. All information

Paste

Finance Application for the TI-89 / TI-92 Plus 5

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To clear all

variable values and reset all options to their defaults, select

TVM

8:Clear Editor

To find out the application software version of the application, select

to close the screen.

Calculating TVM Outside of the TVM Solver

All

TVM

Function calculations outside the value to a

Access a name and

Note: The application and previously-stored data can be overwritten without notification. Avoid using this folder for storing personal data.

If you enter less than six arguments, the calculator substitutes the currently stored variable value for each unspecified argument. If you enter any arguments with a you must place the argument or arguments in parentheses, separated by commas (b).

tvm_N

and finance functions are listed in the

TVM

function takes zero up to six arguments.

TVM Solver

variable use the following syntax:

TVM

value

TVM_variable

finance\

VAR-LINK

precedes a variable name when pasted outside the

TVM_variable

from the

Finance folder (where

VAR-LINK

do NOT save the results in memory. To

menu,

variables are stored) is used by this

TVM

for use outside of the

Finance

folder.

TIFnance

A: About

. Press N or

TVM Solver

precedes a function

TVM Solver

TVM

. Each

save

function,

Use

to save the

new result for i in

The

tvm_N(

tvm_I

The

tvm_I(

memory.

function calculates the number of payment periods.

tvm_N

I,PV,PMT,FV,PPY,CPY

function calculates the interest rate per year.

tvm_I

N,PV,PMT,FV,PPY,CPY

)

is now the

new rate.

Function calculations do not save results in memory.

Finance Application for the TI-89 à TI-92 Plus 6

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tvm_PV

The

tvm_PV

tvm_Pmt

The

tvm_Pmt

tvm_FV

function calculates the present value.

(N,I,

PMT,FV,PPY,CPY

)

function calculates the amount of each payment.

(N,I,PV,FV,

PPY,CPY

)

The

tvm_FV

function calculates the future value of money.

(N,I,

PV,PMT,PPY,CPY

Finance Functions

Catalog

This application adds all Finance functions to the catalog for use in calculations outside of the

TVM Solver

scroll the list of Finance functions. Pressing pastes it to the previous screen in the form of

To solve for a Finance function, include the appropriate arguments (See Argument Definition Table) separated by b and ending with d.

. To access them, press

)

, press … (Flash Apps), and press C and D to

while the indicator points to the name

TIFinance

name

Finance Application for the TI-89 / TI-92 Plus 7

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Sending the Application to Another Calculator with Var-Link

If you send the Finance application to another calculator, the other calculator receives the application, including all finance functions as well as the

variables defined to their

TVM

default values (not as they might be currently defined). If you want to send stored variable values,

send the application, then send the variables using 2

first

Note: After pressing 2 access the

function

names, press ‰ on the TI-92 Plus or 2 ‰ on the TI-89.

Calculating Cash Flows

Use the cash flow functions, periods. You can enter unequal cash flows, which can be cash inflows or outflows. The syntax descriptions for

Catalog Variables/ Arguments Definition

InterestRate,CFO,CFList[CFFreq

npv(

CFO,CFList[,CFFreq

irr(

interest rate

period.

is the initial cash flow at time 0; it must be a real number.

CF0

and

npv(

is the rate by which to discount the cash flows (the cost of money) over one

irr(

, the finance variables are listed in the

npv

and

, to analyze the value of money over equal time

irr

use these arguments.

Finance

folder. To

]) net present value; the sum of the present

values for the cash inflows and outflows. A positive result for

indicates a

npv

profitable investment.

]) internal rate of return; the interest rate at

which the net present value of the cash flows is equal to zero.

CFList

CFFreq

is a list of cash flow amounts after the initial cash flow

is a list in which each element specifies the frequency of occurrence for a

CF0

grouped (consecutive) cash flow amount, which is the corresponding element of The default is 1; if you enter values, they must be positive integers < 10,000.

For example, for the following cash flow function:

5000

6000

CF0 CFList CFFreq

6000

8,000

5000

{6000,L8000,2000,L3000}

{2,2,2,1}

8,000

2000

3,000

CFList

Finance Application for the TI-89 à TI-92 Plus 8

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Calculating Amortization

Use the amortization functions (

bal

Prn

) to calculate balance, sum of principal, and sum

Prn

of interest for an amortization schedule.

Catalog Variables/ Arguments Definition (for an amortization schedule)

npmt[,roundvalue

bal(

PMT1,PMT2[,roundvalue

Int(

PMT1,PMT2

Prn(

is the number of the payment at which you want to calculate a balance. It must be a

npmt

]

)

,[,

roundvalue

]

)

]

)

Schedule balance; based on stored values for I, PV,

The sum of the interest during a specified period. Based on stored values for I, PV,

PMT, PpY

Sum of the principle during a specified period; based on stored values for I, PV,

PMT, PpY

, and

CpY

, and

CpY

positive integer < 10,000.

roundvalue

you do not specify

PMT1

specifies the internal precision the calculator uses to calculate the balance. If

roundvalue

is the starting payment.

, then the calculator uses

is the ending payment in the range.

PMT2

decimal-mode setting.

Float 2

PMT1

and

must be positive integers < 10,000.

To display G on the homescreen, press ¥ and c at the same time, and then press ¤ S.

PMT2

Note: You must enter values for

I, PV

Calculating Interest Conversion

Use the interest conversion functions to convert interest rates from an annual effective rate to a nominal rate,

Catalog Variables/ Arguments Definition

effective_rate,compounding_periods

nom(

nominal_rate,compounding_periods

eff(

effective rate

nominal rate

compounding periods

, or from a nominal rate to an annual effective rate,

Nom

must be a real number.

must be a real number > 0.

, and

before computing the principal.

PMT

Computes the nominal interest rate.

)

Computes the effective interest rate.

Eff

Finance Application for the TI-89 / TI-92 Plus 9

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Finding Days between Dates

Use the date function

dbd(

actual-day-count method.

Catalog Variables/ Arguments Definition

date1,date2

dbd(

date1

and

)

can be numbers or lists of numbers within the range of the dates on the

date2

standard calendar. If both

date1

and

You can enter

must be between the years 1950 through 2049.

date2

and

date1

date2

the date formats.

MM.DDYY (United States)

DDMM.YY (Europe)

Defining Payment Method

The

Pmt_End

annuity due. When you execute either command, the requires any arguments.

and

Pmt_Bgn

to calculate the number of days between two dates using the

Number of days between 2 dates.

date1

and

are lists, they must be the same length.

date2

in either of two formats. The decimal placement differentiates

functions specify a transaction as an ordinary annuity or an

TVM Solver

is updated. Neither function

Pmt_End ( )

Pmt_End

each payment period. Most loans are in this category.

On the

(payment end) specifies an ordinary annuity, where payments occur at the end of

Pmt_End

TVM Solver

’s

PMT:END BEGIN

line, select

END

to set

PMT

Pmt_Bgn ( )

Pmt_Bgn

(payment beginning) specifies an annuity due, where payments occur at the

beginning of each payment period. Most leases are in this category.

On the

TVM Solver

’s

PMT:END BEGIN

line, select

BEGIN

to set

PMT

pmt_at

is a variable which specifies annuity due depending on what value has been stored to

pmt_at

it. If

pmt_at=1

the 2

, then annuity due=

Finance

folder.

Begin

. If

pmt_at=0

, then annuity due=

is the default.

to ordinary annuity.

to annuity due.

. This is located in

End

Finance Application for the TI-89 à TI-92 Plus 10

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Finance Examples

Example 1 — Financing a Car

You have found a car you would like to buy. The car costs $9,000. You can afford payments of $250 per month for four years. What annual percentage rate (APR) will make it possible for you to afford the car?

1. Press highlight

Press

. Press D D B

FIX 2

¸ ¸

to return to

previous screen.

2. Press

3. Highlight and press application. The

Finance

1: FlashApps

with the cursor

to open the

TVM Solver

displayed.

4. Enter known values: N=48;

=9000;

=M250 (Negation

PMT

indicates cash outflow.);

=12 (computes an annual

PpY

percentage rate);

PMT=END

CpY

=12;

=0;

5. Move the cursor to the I% prompt. Press „

Finance Application for the TI-89 / TI-92 Plus 11

Compute

to solve for I%.

Page 12

Example 2 — Calculating Interest on a Fixed Payment

At what annual interest rate, compounded monthly, will $1,250 accumulate to $2,000 in 7 years?

: Because there are no payments when you solve compound interest problems,

Note

be set to

1. Press highlight

Press

and

¸ ¸

must be set to 1.

PpY

. Press D D B

FIX 2

to return to

previous screen.

2. Press

3. Highlight and press application. The

Finance

1: FlashApps

with the cursor

to open the

TVM Solver

displayed.

PMT

must

4. Enter known values: N=7;

=M1250 (Negation indicates

cash outflow or investment.);

=0; FV=2000 (future value is

PMT

cash inflow or return);

=12;

CpY

PMT=END

5. Place the cursor on the

PpY

prompt.

6. Press „ to solve for

, the

annual interest rate.

=1;

Finance Application for the TI-89 à TI-92 Plus 12

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Example 3: — Amortization

You want to buy a home with a 30-year mortgage at 8% APR. Monthly payments are $800. Calculate the outstanding loan balance after each payment and display the results in a graph.

1. Press

highlight

Press

¸ ¸

previous screen.

2. Press

3. Highlight and press application. The displayed.

4. Press

highlight mode.

. Press D D B

FIX 2

to return to

1: FlashApps

Finance

with the cursors

to open the

TVM Solver

. Press B D to

PARAMETRIC

graphing

5. Press the

TVM Solver

¸ ¸

6. Enter known values:

=M800; FV=0;

PMT PMT=END

to return to

PpY

=360; I%=8;

=12;

CpY

=12;

7. Place cursor on the PV prompt.

8. Press „ to solve for

Finance Application for the TI-89 / TI-92 Plus 13

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9. Press ¥ # to display the parametric

editor. Turn off all

stat plots.

10. Press Ü

11. Press

. Press

bal(

define

½ …

12. Press ¥

to define

and highlight

¸ Ü d ¸

bal(T)

to display the

window values. Enter the values below:

Tmin=0 Xmin=0 Ymin=0 Tmax=360 Xmax=360 max=125000 Tstep=12 Xscl=50 Yscl=10000

13. Press ¥

to draw the graph.

as T.

14. Press …

to activate the

Trace

trace cursor. Press B and A to explore the graph of the outstanding balance over time. Press a number and then press

to view the balance at a

specific time

Finance Application for the TI-89 à TI-92 Plus 14

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Error Messages

Message Description

No Sign Change

One or more Enter to overwrite or Escape to return to the Home screen.

TVM Solver

overwrite variable. Exiting application.

TVM Solver

variable is locked or archived. Can not

variables are invalid. Press

You attempted to compute I when FV, (N and

PV are all

‚

0, or when FV, (N

†

PMT),

PMT), and PV

are all  0.

You attempted to compute

CFList

nor

CFO

is > 0, or when no elements of

< 0.

irr( when no elements

An invalid solver variable encountered within the application.

•

Press

to overwrite.

Press N. Go to the Home screen or

VAR-LINK menu to check the variables.

Unarchive or unlock any variables, if necessary. If the value stored to a variable is not a number, delete it or save it as a new a new name. Delete the finance variable.

•

Delete the entire folder

Go to the VAR-LINK menu and unlock or unarchive any variables. If none are locked or archived, delete the variable.

One or more Operation canceled.

TVM Solver

variables are invalid.

If N is defined as a data variable or matrix, rename it and delete the finance variable.

An invalid solver variable encountered outside the application. This applies to

TVM functions and

Amortization functions, which both use the stored

Go to the

TVM Solver variables.

VAR-LINK menu and unlock or

unarchive any variables. If none are locked or archived, delete the variable.

Finance Application for the TI-89 / TI-92 Plus 15

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Error Recovery Instructions

Low Battery Condition

Do not attempt a Flash download if the low-battery message appears on the calculator. Low battery indication is shown on the initial screen. If you receive this error during an installation, change the batteries before trying again.

Memory or Full Memory Error

This error occurs when the TI-89 / TI-92 Plus does not have sufficient memory to store the application. You must delete an application and/or archived variables from the TI-89 / TI-92 Plus in order to make room for another application. You can back up an application to your computer by using the

TI-GRAPH LINK

later using the

Communication Error

This error indicates the Flash Installer is unable to communicate with the TI-89 / TI-92 Plus. The problem is usually associated with the TI-89 / TI-92 Plus and/or to the computer. Make sure the cable is firmly pushed in to the calculator and the computer.

for the TI-89 / TI-92 Plus. Once saved, you can reload it to the TI-89 / TI-92 Plus

Link > Send Flash Software

Link > Receive Flash Application...

menu in

TI-GRAPH LINK

cable and its connection to the

menu in

If this does not correct the problem, try a different

TI-GRAPH LINK

cable and reboot your computer. If you continue to get this error, please contact TI-Caresé Customer Support for assistance.

Flash Application Did Not Install

Follow the steps below to install the flash application.

1. If the

TI-GRAPH LINK

cable was disconnected either from the TI-89 / TI-92 Plus or the

computer, reconnect the cable prior to restarting the installation.

2. Within about 30 seconds after interrupting the download, an error will appear on your computer. Press

¸ ¸

to exit the two error dialog boxes.

3. Reconnect the cable, if necessary.

4. Try to download the application again.

If you continue to have problems, contact TI-Cares.

Validation Error

Either this calculator does not have a certificate to run the application, or electrical interference caused a link to fail. Try to install the application again. If you continue to receive this error, contact TI-Cares.

Checksum Error

The Flash installer was not able to verify that the application was fully installed. Try to download the application again. If this problem persists, contact TI-Cares.

Other Errors

See

Appendix B: Reference Information

(

http://www.ti.com/calc/docs/guides.htm

in the TI-89 / TI-92 Plus Guidebook

) for information about the specific error or contact

TI-Cares.

Finance Application for the TI-89 à TI-92 Plus 16

Page 17

Miscellaneous

Verify Maintenance Upgrade Version and Serial Number

1. From the Home screen, press ƒ.

2. Select

A:ABOUT

The version number has the format

. The serial number appears on the line beneath the

x.yy

product ID number.

Check Amount of Flash Application Free Space

1. Press 2

Select

2:MEM MGMT/DEL...

The Finance application requires at least 36K of RAM memory to load the application. There is approximately 720K total archive memory in the TI-89 / TI-92 Plus. For more information about memory and memory management, refer to the TI-89 / TI-92 Plus guidebook.

The TI-89 / TI-92 Plus guidebook is available in electronic format at

http://www.ti.com/calc/docs/guides.htm.

Finance Application for the TI-89 / TI-92 Plus 17

Page 18

How to Contact Customer Support

Customers in the US, Canada, Mexico, Puerto Rico, and the Virgin Islands

For general questions, contact Texas Instruments Customer Support:

Phone: E-mail:

1.800.TI.CARES (1.800.842.2737) ti-cares@ti.com

For technical questions, call the Programming Assistance Group of Customer Support:

Phone:

1.972.917.8324

Customers outside the US, Canada, Mexico, Puerto Rico, and the Virgin Islands

Contact TI by e-mail or visit the TI calculator home page on the World Wide Web.

E-mail: Internet:

ti-cares@ti.com

http://www.ti.com/calc

Finance Application for the TI-89 à TI-92 Plus 18