Ex 4.4, 18 (MCQ) - Chapter 4 Class 12 Determinants (Important Question)

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Ex 4.4, 18 If A is an invertible matrix of order 2, then det(A−1) is equal to A. det (A) B. 1/(det (A)) C. 1 D. 0 We know that AA-1 = I Taking determinant both sides |"AA−1" |= |I| |A| |A-1| = |I| |A| |A-1| = 1 |A-1| = 1/(|A|) Since |A| ≠ 0 Hence, |A-1| = 1/(|A|) is valid Thus, the correct answer is B

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo