If A is any square matrix of order 3 × 3 such that |A| = 3, then the value of |adj A| is ? 

(a) 3         (b) 1/3  (c) 9           (d) 27

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Question 1 If A is any square matrix of order 3 ร— 3 such that |๐ด| = 3, then the value of |๐‘Ž๐‘‘๐‘— ๐ด| is ? (a) 3 (b) 1/3 (c) 9 (d) 27 We know that |๐‘Ž๐‘‘๐‘— ๐ด| = |A|^(๐‘›โˆ’1) where n is the order of determinant Given Order = n = 3 So, |๐‘Ž๐‘‘๐‘— ๐ด| = |A|^(3โˆ’1) |๐‘Ž๐‘‘๐‘— ๐ด| = |A|^2 |๐‘Ž๐‘‘๐‘— ๐ด| = 32, |๐’‚๐’…๐’‹ ๐‘จ| = 9 So, correct answer is (c) - 9 1 mark

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.