Q18. Matrices A and B will be inverse of each other only if
(A)
(B)
(C)
(D)
We know that if A is a square matrix of order n and there is another matrix B of same order n, such that , then B is inverse of matrix A.
In this case, it is clear that A is inverse of B.
Hence, matrices A and B will be inverse of each other only if .
Option D is correct.