If A is a square matrix of order 3 and |A| = 5, then |adjA|=

(a) 5  

(b) 25  

(c) 125  

(d) 1/5

 

This question is Similar to Question-1 CBSE - Class-12 - Sample-Paper-for-2020-Boards

[MCQ] If A is a square matrix of order 3 and |A| = 5, then |𝑎𝑑𝑗𝐴| - CBSE Class 12 Sample Paper for 2023 Boards

part 2 - Question 13 - CBSE Class 12 Sample Paper for 2023 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

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Transcript

Question 13 If A is a square matrix of order 3 and |A| = 5, then |𝑎𝑑𝑗𝐴|= (a) 5 (b) 25 (c) 125 (d) 1/5 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| = 52 |𝒂𝒅𝒋 𝑨| = 25 So, correct answer is (b)

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