Texas Instruments Titanium TI-89 Quick start guide

Finance Application for the TI-89 / TI-92 Plus 1
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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 àTI-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 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 àTI-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: Ú, æ, 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 Cand Dto move the cursor between variables. After entering a new value, press Dor
¸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
N0
Number of payment periods real number
I0
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.
(ƒ8:Clear Editor)

Finance Application for the TI-89 / TI-92 Plus 5
2. Enter the known values for N, I%,
PV and FV. Press Dor ¸to
save each new value.
3. Enter a value for PpY, which
automatically enters the same
value for CpY; if PpY ƒCpY, 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, ƒ7:Delete
Insertion: 2/
Clear options: M, ƒ8:Clear Editor
The ƒToolbar
The ƒToolbar functions are exactly like the ƒToolbar 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 àTI-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 Nor
¸to close the screen.
Calculating TVM Outside of the TVM Solver
All TVM and finance functions are listed in the ½for 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 iin
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 ½, press …(Flash Apps), and press Cand Dto
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 band ending with d.

Finance Application for the TI-89 àTI-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 6000
6000 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.
ΣInt(PMT1,PMT2[,roundvalue])The sum of the interest during a specified
period. Based on stored values for I, PV,
PMT, PpY, and CpY.
ΣPrn(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 Gon the homescreen, press ¥and cat 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 àTI-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 Solver’s 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 Solver’s 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.