मराठी

If A = [(sin α, cos α), (–cos α, sin α)], then verify that A'A = I

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प्रश्न

If A = `[(sin α, cos α), (-cos α, sin α)]`, then verify that A'A = I

बेरीज
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उत्तर

Given, A =  `[(sin  α, cos α),(-cos α, sin α)]`

So, A' = `[(sin α, -cos α),(cos α, sin α)]`

Now, A' A = `[(sin α, -cos α),(cos α, sin α)] xx [(sin α, cos α),(-cos α, sin α)]`

= `[(sin^2 α + cos^2 α, sin α cos α - cos α sin α),(cos α sin α - sin α cos α, cos^2 α + sin^2 α)]`

= `[(1, 0),(0, 1)]` = I   ...[∵ sin2 α + cos2 α = 1]

Hence, it is proved that, A'A = I

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पाठ 3: Matrices - EXERCISE 3.3 [पृष्ठ ६७]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 3 Matrices
EXERCISE 3.3 | Q 6. (ii) | पृष्ठ ६७

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