Check sibling questions

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


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)

  1. Class 12
  2. Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

About the Author

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo