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CUET · MATHS · PYQ PAPER 2025

Let \(A=\left[\begin{array}{ccc}2 & -1 & 3 \\ 1 & 2 & -1 \\ 4 & 1 & 2\end{array}\right]\). \(M_{i j}\) and \(A_{i j}\) respectively denote the minor and cofactor of an element \(a_{i j}\) of matrix \(A=\left[a_{i j}\right]\).
(A) \(M_{23}=6\)
(B) \(A_{22}=-8\)
(C) \(A_{13}=7\)
(D) \(M_{32}=-5\)
Choose the correct answer from the options given below:

  1. A (A), (C) and (D) only
  2. B (B) and (D) only
  3. C (C) and (D) only
  4. D (A), (B) and (D) only
Verified Solution

Answer & Solution

Correct Answer

(D) (A), (B) and (D) only

Step-by-step Solution

Detailed explanation

\(M_{23} = \det\left[\begin{array}{cc}2 & -1 \\ 4 & 1\end{array}\right]\) \(M_{23} = (2)(1) - (-1)(4) = 2 + 4 = 6\) (A) is correct. \(M_{22} = \det\left[\begin{array}{cc}2 & 3 \\ 4 & 2\end{array}\right]\) \(M_{22} = (2)(2) - (3)(4) = 4 - 12 = -8\)…