ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2025

If A is an invertible matrix of order 3, then
List-IList-II
(A) \(|\operatorname{adj} A|\)(I) \(8|A|\)
(B) \(|A(\operatorname{adj} A)|\)(II) \(|A|^2\)
(C) \(|2 A|\)(III) \(\frac{1}{|A|}\)
(D) \(\left|A^{-1}\right|\)(IV) \(|A|^3\)
Choose the Correct answer from the options given below :

  1. A (A) - (ii), (B) - (iv), (C) - (i), (D) - (iii)
  2. B (A) - (i), (B) - (ii), (C) - (iii), (D) - (iv)
  3. C (A) - (iii), (B) - (iv), (C) - (i), (D) - (ii)
  4. D (A) - (iv), (B) - (iii), (C) - (ii), (D) - (i)
Verified Solution

Answer & Solution

Correct Answer

(A) (A) - (ii), (B) - (iv), (C) - (i), (D) - (iii)

Step-by-step Solution

Detailed explanation

(A) \(|\operatorname{adj} A| = |A|^{n-1} = |A|^{3-1} = |A|^2\) (B) \(|A(\operatorname{adj} A)| = ||A|I| = |A|^n|I| = |A|^3 \cdot 1 = |A|^3\) (C) \(|2 A| = 2^n|A| = 2^3|A| = 8|A|\) (D) \(\left|A^{-1}\right| = \frac{1}{|A|}\) (A) - (II), (B) - (IV), (C) - (I), (D) - (III)