Solution 11716: Calculating the Inverse of a Matrix on the TI-89 Family, TI-92 Family, and Voyage™ 200 Graphing Calculator.
How do I calculate the inverse of a matrix on the TI-89 family, TI-92 family and Voyage 200 graphing calculator?
The example below will demonstrate how to calculate the inverse of a matrix on the TI-89 family, TI-92 family and Voyage 200.
Find the inverse of matrix A:
To enter the matrix:
1) Press [APPS]   (If the Apps Desktop is on, press [APPS], select Data/Matrix Editor, and press .)
2) The type will be Matrix, the name is A and the dimensions are both 2
3) Press [ENTER] twice
4) Input the values that are above in the data matrix editor
To calculate the inverse:
1) Press [HOME]
2) Input a^-1 and press [ENTER]
Please see the TI-89 family, TI-92 family, and Voyage 200 guidebooks for additional information.