# Knowledge Base

## Solution 12160: Storing Formulas in the TI-89 Family, the TI-92 Family, and Voyage™ 200 Graphing Calculators.

### How can I store a formula or equation in my calculator to save calculation time?

There are two ways to store equations in the TI-89 family, TI-92 family, and Voyage 200 to save calculation time, by using the numeric solver or writing a program.

Using the Numeric Solver:

To store the equation a= b*c, for example. Follow the procedure below:

1) Press [APPS]

2) Select 9: Numeric Solver and press [ENTER]. The screen will display "Enter Equation Eqn:"

Please Note: If the Apps Desktop is turned On, Numeric Solver will show as one of the icons on the desktop. Select it and press [ENTER].

3) Type a=b*c and press [ENTER]

The Solver will display each variable, followed by the = sign.

4) Enter the value for each variable, except the unknown variable.

5) Move the cursor next to the unknown variable and press the [F2] key to display the result.

6) Press [2nd] [ESC] to quit the Solver and return to the main screen. After returning to the main screen, the equation is stored in the Numeric Solver. The next time Numeric Solver is opened, the equation will be available to be used. A new equation may be entered as well.

Please Note: A maximum of 11 equations only can be stored in the Numeric Solver.

Write a Program:

Writing a program requires knowledge of the different programming commands and their syntax. The calculator guidebook contains an alphabetical list of operations section that gives all the commands and the proper syntax. Refer to that section for the correct programming syntax.

To solve for the variable a in the equation a=b*c, the following program may be used as an example:

Example()
:Prgm
:Prompt b, c
:b*c -> a
:Disp "a="
:Disp a

Please Note: To get the ->, press the [STO->] key.

When the program above is executed, the user will be prompted to enter a value for b and c. The calculator will then compute and display the value of a.

Users may also consider using the NoteFolio Creator Software and App for added functionality.

Please see the TI-89 family, TI-92 family and Voyage 200 guidebooks for additional information.