ERR:UNDEFINED
Texas Instruments TI-84 Calculator
Severity: MinorWhat it means
ERR:UNDEFINED means you referenced a variable, function, or list that has not been defined.
The variable has no value stored, or you tried to use Y1 without entering an equation.
Store a value or enter the equation first.
Affected Models
- TI-84 Plus
- TI-84 Plus CE
- TI-83 Plus
Common Causes
- Variable referenced but never assigned a value
- Y= equation not entered but referenced in a calculation
- List referenced that does not exist or was cleared
- Program references a variable that was not initialized
How to Fix It
-
Store a value in the variable.
To store: type the value, press STO>, press the variable letter.
Example: 5 STO> X stores 5 in X. -
If using Y1, Y2, etc.: enter the equations in the Y= editor.
Press Y= and type your equations.
You must define them before using them in calculations. -
For lists: make sure the list exists with data.
Go to STAT > Edit and check if the list has entries.
Create the list if it does not exist.
Frequently Asked Questions
How do I clear all variables?
2nd > MEM > 2:Mem Mgmt/Del > 2:Real > select and delete.
Or 2nd > MEM > 4:ClrAllLists clears all list data.
Can variables persist between power offs?
Yes.
Variables are stored in RAM and persist until you clear them or reset the calculator.