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Question
Answer the following question:
If A = `[(2, -1),(3, -2)]`, find A3
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Solution
A2 = A.A = `[(2, -1),(3, -2)] [(2, -1),(3, -2)]`
= `[(4 - 3, -2 + 2),(6 - 6, -3 + 4)]`
∴ A2 = `[(1, 0),(0, 1)]`
∴ A2 = I
Multiplying throughout by A, we get
A3 = A.I
∴ A3 = A
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