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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Transcript

Question 1 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 We know that |𝑎𝑑𝑗 𝐴| = |A|^(𝑛−1) where n is the order of determinant Given Order = n = 3 So, |𝑎𝑑𝑗 𝐴| = |A|^(3−1) |𝑎𝑑𝑗 𝐴| = |A|^2 |𝑎𝑑𝑗 𝐴| = 32, |𝒂𝒅𝒋 𝑨| = 9 So, correct answer is (c) - 9 1 mark

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.