Given that A is a square matrix of order 3 and |A| = −4, then adj A| is equal to:

(a) −4     (b) 4
(c) −16   (d) 16

This question is inspired from Question 5 (Choice 2) - CBSE Class 12 Sample Paper for 2021 Boards

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Transcript

Question 6 Given that A is a square matrix of order 3 and |A| = −4, then adj A| is equal to: (a) −4 (b) 4 (c) −16 (d) 16 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| = (−4)2 |𝒂𝒅𝒋 𝑨| = 16 So, the correct answer is (d)

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Davneet Singh

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.