ERR:UNDEFINED
Texas Instruments TI-84 Calculator
Severity: MinorWhat Does This Error Mean?
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
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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.
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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.
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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.