HP 50G - The Identity Matrix; The Inverse Matrix

Page 9-7
The identity matrix
The identity matrix has the property that A⋅I = I⋅A = A. To verify this
property we present the following examples using the matrices stored
earlier on. Use function IDN (find it in the MTH/MATRIX/MAKE menu) to
generate the identity matrix as shown here:
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). Examples of the inverse of some of the matrices stored
earlier are presented next:
To verify the properties of the inverse matrix, we present the following
multiplications:
SG49A.book Page 7 Friday, September 16, 2005 1:31 PM