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Prove that (A–1)′ = (A′)–1, where A is an invertible matrix. - Mathematics

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प्रश्न

Prove that (A–1)′ = (A′)–1, where A is an invertible matrix.

योग
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उत्तर

Since A is an invertible matrix, so it is non-singular

We know that |A| = |A′|.

But |A| ≠ 0.

So |A′| ≠ 0 i.e. A′ is invertible matrix.

Now we know that AA–1 = A–1A = I.

Taking transpose on both sides, we get

(A–1)′A′ = A′(A–1)′

= (I)′

= I

Hence (A–1)′ is inverse of A′

i.e., (A′)–1 = (A–1)

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अध्याय 4: Determinants - Solved Examples [पृष्ठ ७१]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 12
अध्याय 4 Determinants
Solved Examples | Q 6 | पृष्ठ ७१

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