If A is an invertible matrix of order 2, then det (A–1) is equal to

If A is an invertible matrix of order 2, then det (A–1) is equal to

(A) det            (A)       (B)1/det (A)               (C) 1               (D) 0

We have the formula

AA^-1 = I

Take determinant both side we get

|A ||A^-1| = 1

Divide by |A| both side we get

|A^-1| = 1/|A |

Hence option B is correct