Use the error name to locate the input, list, matrix or graph setting that needs attention.
ERR: INVALID DIM and DIM MISMATCH
INVALID DIM often appears when a stat plot is enabled but its lists are empty or unsuitable for the selected plot type. Open STAT PLOT and turn unused plots off, or fill the required lists.
DIM MISMATCH means lists or matrices used together have incompatible sizes. For a scatterplot, L1 and L2 must contain the same number of values.
Fast INVALID DIM checklist
- Press 2nd → Y= to open STAT PLOT.
- Turn Plot1, Plot2 and Plot3 off unless needed.
- Check L1 and L2 lengths in STAT → EDIT.
- Press GRAPH again.
ERR: DOMAIN
The input is outside the real-number domain, such as √(-1) in real mode, log(0), or sin⁻¹(2).
ERR: SYNTAX
Look near the cursor for missing parentheses, misplaced commas, repeated operators or an incomplete function.
Matrix errors
SINGULAR MAT
The determinant is zero, so an inverse does not exist.
DIM MISMATCH
The inner dimensions do not match for multiplication.
ERR: WINDOW RANGE
Each minimum must be less than its corresponding maximum. For example, Xmin must be less than Xmax.
Practice diagnosis
A scatterplot uses five values in L1 and four values in L2. Which error is most likely?
Reveal the answer
DIM MISMATCH, because the paired lists have different lengths.
Practice with the calculator open
Use the guide in one tab and the calculator in another.
Editorial note: This guide is independently written for classroom practice and was reviewed against the TI-84 Plus CE guidebook. Button labels and menu availability can vary by model and operating-system version.