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CUET · MATHS · PYQ PAPER 2025

If \(A=\left[\begin{array}{cc}3 & 1 \\ -1 & 2\end{array}\right]\) and \(I=\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]\), then the value of \(A^2-5 A+6 I\) is

  1. A \(\left[\begin{array}{cc}-1 & 0 \\ 0 & -1\end{array}\right]\)
  2. B \(\left[\begin{array}{ll}0 & 0 \\ 0 & 0\end{array}\right]\)
  3. C \(\left[\begin{array}{ll}1 & 1 \\ 1 & 1\end{array}\right]\)
  4. D \(\left[\begin{array}{cc}0 & -1 \\ -1 & 0\end{array}\right]\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\left[\begin{array}{cc}-1 & 0 \\ 0 & -1\end{array}\right]\)

Step-by-step Solution

Detailed explanation

\(A^2 = \left[\begin{array}{cc}3 & 1 \\ -1 & 2\end{array}\right]\left[\begin{array}{cc}3 & 1 \\ -1 & 2\end{array}\right] = \left[\begin{array}{cc}9-1 & 3+2 \\ -3-2 & -1+4\end{array}\right] = \left[\begin{array}{cc}8 & 5 \\ -5 & 3\end{array}\right]\)…