HP 48gII - Manual (Page 332)

Page 11-6
The inverse matrix
The inverse of a square matrix
A is the matrix A -1 such that A⋅A -1 = A -1 ⋅A = I,
where I is the identity matrix of the same dimensions as A. The inverse of a
matrix is obtained in the calculator by using the inverse function, INV (i.e., the
Y key). An example of the inverse of one of the matrices stored earlier is
presented next:
To verify the properties of the inverse matrix, we present the following
multiplications:
Characterizing a matrix (The matrix NORM menu)
The matrix NORM (NORMALIZE) menu is accessed through the keystroke
sequence
„´ (system flag 117 set to CHOOSE boxes):
This menu contains the following functions: