हिंदी

If A = [(α, β),(γ, –α)] is such that A^2 = I, then ______.

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प्रश्न

If A = `[(α, β),(γ, -α)]` is such that A2 = I, then ______.

विकल्प

  • 1 + α2 + βγ = 0

  • 1 – α2 + βγ = 0

  • 1 – α2 – βγ = 0

  • 1 + α2 – βγ = 0

MCQ
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उत्तर

If A = `[(α, β),(γ, -α)]` is such that A2 = I, then 1 – α2 – βγ = 0.

Explanation:

A = `[(α, β), (γ, -α)]`

`A^2 = A * A [(α, β), (γ, -α)][(α, β), (γ, -α)]`

= `[(α^2 + βγ, αβ - αβ), (αγ - αγ, βγ + α^2)] = [(1, 0), (0, 1)]`

Now, A2 = I

⇒ `[(α^2 + βγ,0), (0, βγ + α^2)] = [(1, 0), (0, 1)]`

α2 + βγ = 1 or 1 – α2 – βγ = 0

Accordingly, option (1 – α2 – βγ = 0) is correct.

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अध्याय 3: Matrices - Miscellaneous Exercise on Chapter 3 [पृष्ठ ७३]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 3 Matrices
Miscellaneous Exercise on Chapter 3 | Q 9. | पृष्ठ ७३

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