Texas Instruments TI-89 User Manual | Manualsnet (2024)

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

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 2

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.

2000 Texas Instruments Incorporated TINGRAPH LINK and TI-Cares are trademarks of Texas Instruments Incorporated.

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

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 LINK. 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 4

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

Use Time-Value-of-Money (TVM) functions to analyze financial instruments such as annuities, loans, mortgages, leases, and savings.

The TVM Solver screen automatically displays when you run the Finance application. It displays the time-value-of-money (TVM) variables: , , PV, PMT, FV. Given four variable values, the TVM Solver solves for the fifth variable.

To access the variables outside the TVM editor, press 2 . They are located in the Finance folder. Note: Exit the TVM Solver, and then press 2 to display the TVM variables. Otherwise, the variable currently highlighted by the cursor in the TVM Solver will not display in the VAR-LINK variable list.

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 Compute or .

Note: The VAR-LINK Finance folder (where TVM variables are stored) is used by this application and previously-stored data can be overwritten without notification. Avoid using this folder for storing personal data.

TVM variables Default Definition Value Type

N 0 Number of payment periods real number

I 0 Annual interest rate (converted to a per-period rate based on the values of PpY and CpY)

real number

PV 0 Present value real number

PMT 0 Payment amount real number

FV 0 Future value real number

PpY 1 Payments per year integer > 0

CpY 1 Compounding periods per year integer > 0

END BEGIN

END Set annuity due (i.e. specify whether payment is at the end or beginning of each period)

N/A

When you store a value to PpY in the TVM Solver only, the value for CpY automatically changes to the same value. To store a unique value to CpY, you must store the value to CpY after you have stored a value to PpY. If you store a value to PpY outside the TVM Solver, the value for CpY does not change.

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

To solve for an unknown TVM variable, follow these steps.

1. Press O to display the TVM Solver.

Highlight Finance with cursor and press .

Default TVM values. ( 8:Clear Editor)

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

2. Enter the known values for N, I%, PV and FV. Press D or to save each new value.

3. Enter a value for PpY, which automatically enters the same value for CpY; if PpY CpY, enter a unique value for CpY.

4. Select END or BEGIN to specify the payment method by highlighting the option with the cursor and pressing .

5. Place the cursor on the TVM variable for which you want to solve (i.e. PMT).

6. Press Compute. The answer is computed and displayed and stored to the appropriate TVM variable. An indicator calculator in the left column designates the solution variable.

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 B

Deletion options: 0, 0, 7:Delete

Insertion: 2 /

Clear options: M, 8:Clear Editor

The Toolbar

The Toolbar functions are exactly like the Toolbar on the TI-89 and TI-92 Plus on the Home screen. You can Cut, Copy, and Paste information within the TVM Solver. All information is placed on the calculator clipboard for use either within or outside the application. Paste 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.

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

To clear all TVM variable values and reset all options to their defaults, select 8:Clear Editor.

To find out the application software version of the application, select A: About. Press N or to close the screen.

Calculating TVM Outside of the TVM Solver

All TVM and finance functions are listed in the for use outside of the TVM Solver. Each TVM function takes zero up to six arguments.

Function calculations outside the TVM Solver do NOT save the results in memory. To save a value to a TVM variable use the following syntax:

value TVM_variable

Access a TVM_variable from the VAR-LINK menu, Finance folder. TIFnance precedes a function name and finance\ precedes a variable name when pasted outside the TVM Solver.

Note: The VAR-LINK Finance folder (where TVM variables are stored) is used by this 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 TVM variable value for each unspecified argument. If you enter any arguments with a TVM function, you must place the argument or arguments in parentheses, separated by commas (b).

tvm_N

The tvm_N function calculates the number of payment periods.

tvm_N(I,PV,PMT,FV,PPY,CPY)

tvm_I

The tvm_I function calculates the interest rate per year.

tvm_I(N,PV,PMT,FV,PPY,CPY)

I% is now the new rate.

Function calculations do not save results in memory.

Use to save the new result for i in

memory.

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

tvm_PV

The tvm_PV function calculates the present value.

tvm_PV(N,I,PMT,FV,PPY,CPY)

tvm_Pmt

The tvm_Pmt function calculates the amount of each payment.

tvm_Pmt(N,I,PV,FV,PPY,CPY)

tvm_FV

The tvm_FV function calculates the future value of money.

tvm_FV(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. To access them, press , press (Flash Apps), and press C and D to scroll the list of Finance functions. Pressing while the indicator points to the name pastes it to the previous screen in the form of TIFinance.name.

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

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

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 TVM variables defined to their default values (not as they might be currently defined). If you want to send stored variable values, first send the application, then send the variables using 2 .

Note: After pressing 2 , the finance variables are listed in the Finance folder. To access the function names, press on the TI-92 Plus or 2 on the TI-89.

Calculating Cash Flows

Use the cash flow functions, npv and irr, to analyze the value of money over equal time periods. You can enter unequal cash flows, which can be cash inflows or outflows. The syntax descriptions for npv( and irr( use these arguments.

Catalog Variables/ Arguments Definition

npv(InterestRate,CFO,CFList[CFFreq]) net present value; the sum of the present values for the cash inflows and outflows. A positive result for npv indicates a profitable investment.

irr(CFO,CFList[,CFFreq]) internal rate of return; the interest rate at which the net present value of the cash flows is equal to zero.

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

CF0 is the initial cash flow at time 0; it must be a real number.

CFList is a list of cash flow amounts after the initial cash flow CF0.

CFFreq is a list in which each element specifies the frequency of occurrence for a grouped (consecutive) cash flow amount, which is the corresponding element of CFList. The default is 1; if you enter values, they must be positive integers < 10,000.

For example, for the following cash flow function:

CF0 = 5000 CFList = {6000,L8000,2000,L3000} CFFreq = {2,2,2,1}

5000 60006000 2000

M8,000

2000

M8,000 M3,000

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

Calculating Amortization

Use the amortization functions (bal, GPrn,GPrn) to calculate balance, sum of principal, and sum of interest for an amortization schedule.

Catalog Variables/ Arguments Definition (for an amortization schedule)

bal(npmt[,roundvalue]) Schedule balance; based on stored values for I, PV, PMT, PpY, and CpY.

Int(PMT1,PMT2[,roundvalue]) The sum of the interest during a specified period. Based on stored values for I, PV, PMT, PpY, and CpY.

Prn(PMT1,PMT2,[,roundvalue]) Sum of the principle during a specified period; based on stored values for I, PV, PMT, PpY, and CpY.

npmt is the number of the payment at which you want to calculate a balance. It must be a positive integer < 10,000.

roundvalue specifies the internal precision the calculator uses to calculate the balance. If you do not specify roundvalue, then the calculator uses Float 2 decimal-mode setting.

PMT1 is the starting payment. PMT2 is the ending payment in the range. PMT1 and PMT2

must be positive integers < 10,000.

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

Note: You must enter values for I, PV, and PMT before computing the principal.

Calculating Interest Conversion

Use the interest conversion functions to convert interest rates from an annual effective rate to a nominal rate, 4Nom, or from a nominal rate to an annual effective rate, 4Eff.

Catalog Variables/ Arguments Definition

nom(effective_rate,compounding_periods) Computes the nominal interest rate.

eff(nominal_rate,compounding_periods) Computes the effective interest rate.

effective rate must be a real number.

nominal rate must be a real number.

compounding periods must be a real number > 0.

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

Finding Days between Dates

Use the date function dbd( to calculate the number of days between two dates using the actual-day-count method.

Catalog Variables/ Arguments Definition

dbd(date1,date2) Number of days between 2 dates.

date1 and date2 can be numbers or lists of numbers within the range of the dates on the standard calendar. If both date1 and date2 are lists, they must be the same length.

date1 and date2 must be between the years 1950 through 2049.

You can enter date1 and date2 in either of two formats. The decimal placement differentiates the date formats.

MM.DDYY (United States)

DDMM.YY (Europe)

Defining Payment Method

The Pmt_End and Pmt_Bgn functions specify a transaction as an ordinary annuity or an annuity due. When you execute either command, the TVM Solver is updated. Neither function requires any arguments.

Pmt_End ( )

Pmt_End (payment end) specifies an ordinary annuity, where payments occur at the end of each payment period. Most loans are in this category. Pmt_End is the default.

On the TVM Solvers PMT:END BEGIN line, select END to set PMT to ordinary annuity.

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 Solvers PMT:END BEGIN line, select BEGIN to set PMT to annuity due.

pmt_at

pmt_at is a variable which specifies annuity due depending on what value has been stored to it. If pmt_at=1, then annuity due=Begin. If pmt_at=0, then annuity due=End. This is located in the 2 Finance folder.

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

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 3. Press D D B 3 to highlight FIX 2.

Press to return to previous screen.

2. Press O 1: FlashApps .

3. Highlight Finance with the cursor and press to open the application. The TVM Solver is displayed.

4. Enter known values: N=48; PV=9000; PMT=M250 (Negation indicates cash outflow.); FV=0; PpY=12 (computes an annual percentage rate); CpY=12; PMT=END.

5. Move the cursor to the I% prompt. Press Compute to solve for I%.

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

Note: Because there are no payments when you solve compound interest problems, PMT must be set to 0 and PpY must beset to 1.

1. Press 3. Press D D B 3 to highlight FIX 2.

Press to return to previous screen.

2. Press O 1: FlashApps .

3. Highlight Finance with the cursor and press to open the application. The TVM Solver is displayed.

4. Enter known values: N=7; PV=M1250 (Negation indicates cash outflow or investment.); PMT=0; FV=2000 (future value is cash inflow or return); PpY=1; CpY=12; PMT=END.

5. Place the cursor on the I% prompt.

6. Press to solve for I%, the annual interest rate.

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

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 3. Press D D B 3 to highlight FIX 2.

Press to return to previous screen.

2. Press O 1: FlashApps .

3. Highlight Finance with the cursors and press to open the application. The TVM Solver is displayed.

4. Press 3. Press B D to highlight PARAMETRIC graphing mode.

5. Press to return to the TVM Solver.

6. Enter known values: N=360; I%=8; PMT=M800; FV=0; PpY=12; CpY=12; PMT=END.

7. Place cursor on the PV prompt.

8. Press to solve for PV.

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

9. Press # to display the parametric Y= editor. Turn off all stat plots.

10. Press to define XT1 as T.

11. Press and highlight bal(. Press d to define YT1 as bal(T).

12. Press $ 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.

14. Press Trace to activate the 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 T.

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

Error Messages

Message Description

No Sign Change You attempted to compute I when FV, (NPMT), and PV are all 0, or when FV, (NPMT), and PV are all 0.

You attempted to compute irr( when no elements of CFList nor CFO is > 0, or when no elements of CFList nor CFO < 0.

One or more TVM Solver variables are invalid. Press Enter to overwrite or Escape to return to the Home screen.

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

TVM Solver variable is locked or archived. Can not overwrite variable. Exiting application.

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

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

One or more TVM Solver variables are invalid. Operation canceled.

An invalid solver variable encountered outside the application. This applies to TVM functions and Amortization functions, which both use the stored TVM Solver variables.

Go to the 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 16

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 Link > Receive Flash Application... menu in TI-GRAPH LINK for the TI-89 / TI-92 Plus. Once saved, you can reload it to the TI-89 / TI-92 Plus later using the Link > Send Flash Software menu in TI-GRAPH LINK.

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-GRAPH LINK cable and its connection to 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.

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-Cares 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 in the TI-89 / TI-92 Plus Guidebook (http://www.ti.com/calc/docs/guides.htm ) for information about the specific error or contact TI-Cares.

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

Miscellaneous

Verify Maintenance Upgrade Version and Serial Number

1. From the Home screen, press .

2. Select A:ABOUT.

The version number has the format x.yy. The serial number appears on the line beneath the product ID number.

Check Amount of Flash Application Free Space

1. Press 2 .

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

For technical questions, call the Programming Assistance Group of Customer