Matrix Inverse: Matrix Inversion Technique
Matrix Inversion Technique The inverse of a matrix The inverse of a square n × n matrix A is another n × n matrix denoted by A -1 such that AA -1 =A -1 A=I where I is the n × n identity matrix. That is, multiplying a matrix by its inverse produces an identity matrix. Not all square matrices have an inverse matrix. If the determinant of the matrix is zero, then it will not have an inverse, and the matrix is said to be singular. Only non-singular matrices have inverses. A formula for finding the inverse Given any non-singular matrix A, its inverse can be found from the formula A -1 = adj A |A| where adj A is the adjoint matrix and |A| is the determinant of A. The procedure for finding the adjoint matrix is given below. Finding the adjoint matrix The adjoint of a matrix A is found in stages: Find the transpose of A, which is denoted by A T . The transpose is found by interchanging the rows and columns of A. So, for example, the first column of A is the first row of the transpo