In number arithmetic every number ( ) has a reciprocal written as or such that . Some, but not all, square matrices have inverses. If a square matrix has an inverse, , then
We develop a rule for finding the inverse of a matrix (where it exists) and we look at two methods of finding the inverse of a matrix (where it exists).
Non-square matrices do not possess inverses so this Section only refers to square matrices.
- be familiar with the algebra of matrices
- be able to calculate a determinant
- know what a cofactor is
- state the condition for the existence of an inverse matrix
use the formula for finding the inverse of
- find the inverse of a matrix using row operations and using the determinant method