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

Last updated at April 16, 2024 by

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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, Social Science, Physics, Chemistry, Computer Science at Teachoo.