If A = 
2
1
1
1
2
1
1
1
2
−
−
−
−








Verify that A3 – 6A2 + 9A – 4I = O and hence find A–1
17 Let A be a nonsingular square matrix of order 3 × 3 Then |adj A| is equal to
(A) | A |
(B) | A |2
(C) | A |3
(D) 3|A|
18 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
4