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CUET · MATHS · PYQ PAPER 2025

If the matrix \(A =\left(\begin{array}{ll}1 & 3 \\ 2 & 1\end{array}\right)\), then the value of \(\operatorname{det}\left( A ^2-2 A \right)\) is equal to

  1. A 5
  2. B \(-5\)
  3. C 25
  4. D \(-25\)
Verified Solution

Answer & Solution

Correct Answer

(C) 25

Step-by-step Solution

Detailed explanation

\(\operatorname{det}(A) = 1(1) - 3(2) = -5\) \(A - 2I = \left(\begin{array}{ll}1 & 3 \\ 2 & 1\end{array}\right) - \left(\begin{array}{ll}2 & 0 \\ 0 & 2\end{array}\right) = \left(\begin{array}{rr}-1 & 3 \\ 2 & -1\end{array}\right)\)…