CASTI-89 TITANIUM · CALC89
DelVar
Deletes variables from memory so they are undefined again. This matters for symbolic work, because a stored value would otherwise be substituted into every result.
Syntax
DelVar var[, var…]
- Group
- Variables and memory
- Arguments
- Takes one or more variable names, separated by commas.
- Availability
- Included
- Menu path
- F4 Other ▸ DelVar
Example
| Input | Result |
|---|---|
| 5→a | 5 |
| DelVar a | Done |
| a | a |
Entered line by line, 5→a returns 5, then DelVar a returns Done, then a returns a.
Keystrokes on the TI-89 Titanium
F42
The same key sequence inserts DelVar in Calc89, and the AI tutor shows it step by step on the on-screen keypad.
Related commands
- getLockInfo(Returns 1 if a variable is locked and 0 if it is not.
- LockLocks variables so they cannot be changed or deleted until they are unlocked.
- NewProbStarts a new problem by clearing single letter variables, so values stored earlier do not affect new calculations.
- unLockUnlocks variables that were locked with Lock, so they can be changed or deleted again.
- DefineDefines a user function or variable that can be used in later calculations, for example f(x).