हिंदी

If A is a square matrix such that A^2 = A, then (I + A)^3 – 7A is equal to ______.

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प्रश्न

If A is a square matrix such that A2 = A, then (I + A)3 – 7A is equal to ______.

विकल्प

  • A

  • I – A

  • I

  • 3A

MCQ
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उत्तर

If A is a square matrix such that A2 = A, then (I + A)3 – 7A is equal to I.

Explanation:

Given: A2 = A

∵ A3 = A2. A

= A.A = A2 = A

∴ (I + A)3 – 7A = I3 + 3i2A + 3IA2 + A3 – 7A

= I3 + 3IA + 3IA2 + A3 – 7A

= I + 3A + 3A2 + A3 – 7A

= I + 3A + 3A + A2 . A – 7A

= I + 3A + 3A + A – 7A

= 7A – 7A + I

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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 11. | पृष्ठ ७३

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