Notice that the matrix of cofactors has been transposed and divided by |B| to obtainB^(-1). It is left as an exercise to verify that this is the inverse of B. As with the determinants, computers are used to find the inverses of larger matrices.
Note that if A is a diagonal nonsingular matrix, then A^(-1) is also a Inverse of a Diagonal Matrix diagonal matrix where the diagonal elements of A^(-1) are the reciprocals of the diagonal elements of A. That is, if