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If A = [1241], find A2 + 2A + 7I. - Mathematics

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Question

If A = `[(1, 2),(4, 1)]`, find A2 + 2A + 7I.

Sum

Solution

We have, A = [(1, 2),(4, 1)]`

∴ A2 = A · A

= `[(1,  2),(4, 1)] [(1, 2),(4, 1)]`

= `[(1 + 8, 2 + 2),(4 + 4, 8 + 1)]`

= `[(9, 4),(8, 9)]`

∴ A2 + 2A + 7I = `[(9, 4),(8, 9)] + [(2, 4),(8, 2)] + [(7, 0),(0, 7)]`

= `[(18, 8),(16, 18)]`

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Chapter 3: Matrices - Exercise [Page 58]

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NCERT Exemplar Mathematics [English] Class 12
Chapter 3 Matrices
Exercise | Q 43 | Page 58

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