Texas Instruments TI 84 User Guide - Page 646

If you are using trigonometric functions or performing polar and rectangular conversions, the unexpected results may be caused by an angle mode setting. The Radian and Degree angle mode settings control how the TI-84 Plus interprets angle values. To change the angle mode settings, follow these steps: 1. Press z to display the Mode settings. 2. Select Degree or Radian. 3. Press Í to save the angle mode setting. ERR:DIM MISMATCH Error Your TI-84 Plus displays the ERR:DIM MISMATCH error if you are trying to perform an operation that references one or more lists or matrices whose dimensions do not match. For example, multiplying L1*L2, where L1={1,2,3,4,5} and L2={1,2} produces an ERR:DIM MISMATCH error because the number of elements in L1 and L2 do not match. ERR:INVALID DIM Error The ERR:INVALID DIM error message may occur if you are trying to graph a function that does not involve the stat plot features. The error can be corrected by turning off the stat plots. To turn the stat plots off, press y , and then select 4:PlotsOff. Contrast Feature If the contrast setting is too dark (set to 9) or too dim (set to 0) the unit may appear as if it is malfunctioning or turned off. To adjust the contrast, press and release y, and then press and hold } or †. Appendix B: Reference Information 643