## The inverse of a matrix

Why inverse matrices? The inverse of a matrix is also called the reciprocal of the matrix. Since matrices cannot be divided, inverse matrices are used as the reciprocal operation of multiplication of matrices. Notation If A is a square matrix, then its inverse is also a square matrix and it is denoted by A−1. AA−1 = I, where I is the identity matrix. For example, in the equation AX = B, where A, X and B are matrices, X = A−1B. Invertible matrices must be square matrices (the number of rows equals the number of columns). Here are some square matrices: (2 × 2) (3 × 3) (4 × 4) ...