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

CBSE Class 12 Sample Paper for 2023 Boards
CBSE Class 12 Sample Paper for 2023 Boards
Last updated at Dec. 13, 2024 by Teachoo
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)