Texas Instruments Titanium TI-89 User Manual

Symbolic Manipulation 236
Determining If a Variable Is Exists
Determining If a Variable Is ExistsDetermining If a Variable Is Exists
Determining If a Variable Is Exists
• If x is defined, the result may be in a form
you did not expect.
Note: When defining a variable, it’s a good
practice to use more than one character
in the name. Leave one-character names
undefined for symbolic calculations.
Method: Example:
Enter the variable name.
Use the
isVar() function.
Unless you knew that
5 had been stored to
x previously, the
answer 75 could be
misleading.
If defined, the variable’s
value is displayed.
If undefined, the variable
name is displayed.
If defined, “true” is
displayed.
If undefined, “false” is
displayed.

Texas Instruments Titanium TI-89 Specifications

General

Brand	Texas Instruments
Model	Titanium TI-89
Category	Calculator
Language	English