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प्रश्न
If A = `[(1, 0, 0),(0, 1, 0),("a", "b", - 1)]`, show that A2 is a unit matrix
उत्तर
A = `[(1, 0, 0),(0, 1, 0),("a", "b", - 1)]`
A2 = A . A
= `[(1, 0, 0),(0, 1, 0),("a", "b", - 1)] [(1, 0, 0),(0, 1, 0),("a", "b", -1)]`
= `[(1 + 0 + 0, 0 + 0 + 0, 0 + 0 + 0),(0 + 0 + 0, 0 + 1 + 0, 0 + 0 + 0),("a" + 0 - "a", 0 + "b" - "b", 0 + 0 +1)]`
A2 = `[(1, 0, 0),(0, 1, 0),(0, 0, 1)]`
Thus, A2 is a unit matrix.
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