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

If A is square matrix of order 3 x 3 such that |A| = 3, then |adj A|

Question 1 - CBSE Class 12 Sample Paper for 2020 Boards - Part 2

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

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