Ex 3.3, 5 (ii) - Chapter 3 Class 12 Matrices (Term 1)

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Ex 3.3, 5 For the matrices A and B, verify that (AB) = B A , where (ii) A = [ 8(0@1@2)] , B = [1 5 7] Taking L.H.S (AB) Finding AB AB = [ 8(0@1@2)]_(3 1) "[1 5 7]" _(1 3) = [ 8(0 1&0 5&0 7@1 1&1 5&1 7@2 1&2 5&2 7)]_(3 3) = [ 8(0&0&0@1&5&7@2&10&14)] Thus, AB = [ 8(0&0&0@1&5&7@2&10&14)] So, (AB) = [ 8(0&1&2@0&5&10@0&7&14)] Taking R.H.S (B A ) Finding B B = [1 5 7] B = [ 8(1@5@7)] Also, A = [ 8(0@1@2)] A = [0 1 2] B A = [ 8(1@5@7)]_(3 1) "[0 1 2] " _(1 3) = [ 8(1 0&1 1&1 2@5 0&5 1&5 2@7 0&7 1&7 2)]_(3 3) = [ 8(0&1&2@0&5&10@0&7&14)] = L.H.S Hence L.H.S = R.H.S Hence proved