ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2025

If \(A\) is a non-singular matrix of order 3 such that \(|\operatorname{adj}(A)|=121\), then \(\left|A A^T\right|\) is equal to :

  1. A 121
  2. B 21
  3. C 63
  4. D 11
Verified Solution

Answer & Solution

Correct Answer

(A) 121

Step-by-step Solution

Detailed explanation

\(|\operatorname{adj}(A)| = |A|^{n-1}\) \(121 = |A|^{3-1}\) \(121 = |A|^2\) \(|AA^T| = |A||A^T|\) \(|AA^T| = |A||A|\) \(|AA^T| = |A|^2\) \(|AA^T| = 121\)