Sharing, or linking, the variables you create is a powerful tool for math exploration. The display of linked variables is automatically updated when the variable’s value changes.
Linking to Shared Variables
To use a stored variable:
| 1. | Display the page and select the location or object to which you want to link a variable. |
| 2. | Select the Variables tool h. |
The Variables options are displayed. The software knows which types of variables will work in the location or with the object selected and will only display those variables.
| 3. | Use 9 and : to scroll the list. |
—or—
Type part of the variable name.
As you type, the system displays a list of variables that begin with the letters you typed. Typing part of the name enables you to locate a variable more quickly if the list is long.
| 4. | When you locate and highlight the name of the variable you want to use, click the name. |
—or—
Press ·.
The selected variable value is linked.
When you link a cell to a variable, Lists & Spreadsheet keeps the cell value updated to reflect the current value of the variable. The variable can be any variable in the current problem and can be defined in Graphs & Geometry, Calculator, or any instance of Lists & Spreadsheet.
Note: Do not link to a system variable. Doing so could prevent the variable from being updated by the system. System variables include ans, StatMatrix, and statistics results (such as RegEqn, dfError, and Resid).
| 1. | Click the cell that you want to link to the variable. |
| 2. | Open the VarLink menu: |
| - | Click  , and then click Cell. |
| - | Handheld: Press h. |
The VarLink menu is displayed.
| 3. | Under Link To, scroll to the name of the variable and click it. |
The cell shows the value of the variable.
After storing a value in a variable, you can use the variable name in an expression as a substitute for the stored value.
| 1. | Enter the expression: |
| - | Type 4*25*num^2 on the entry line, and press Enter. |
| - | Handheld: Type 4 r 25 r num q on the entry line, and press ·. |
Calculator substitutes 517, the value currently assigned to num, and evaluates the expression.
| 2. | Enter the expression: |
| - | Type 4*25*nonum^2, and press Enter. |
| - | Handheld: Type 4 r 25 r nonum q on the entry line, and press ·. |
CAS: Because the variable nonum has not been defined, it is treated algebraically in the result.
Because the variable nonum has not been defined, the expression returns an error message.