Q34 of 74 Page 7

If , find A–1 and prove that A2 – 4A–5I = O.

A =


A2 =


=


=


A2 – 4A + 5I = 0


=


=


=


Also, A2 – 4A – 5I = 0


Now, 6(A.A) A – 1 – 4.A A – 1 – 5I.A – 1 = 0


= A – 4I – 5A – 1 = 0


= A – 1 =


=


=


Hence, A – 1 =


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