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CUET · MATHS · PYQ PAPER 2025

If \(A=\left|\begin{array}{ccc}x & -3 & 4 \\ 3 & y & -5 \\ -4 & z & 0\end{array}\right|\) is a Skew-Symmetric matrix and \(a d j A=\left[a_{i j}\right]_{3 \times 3}\), then \(a_{11}+a_{22}+a_{33}\) is equal to:

  1. A \(32\)
  2. B \(0\)
  3. C \(50\)
  4. D \(18\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(50\)

Step-by-step Solution

Detailed explanation

For a Skew-Symmetric matrix, \(a_{ii}=0\) and \(a_{ij}=-a_{ji}\). \(x=0, y=0, z=5\). \(A=\begin{pmatrix}0 & -3 & 4 \\ 3 & 0 & -5 \\ -4 & 5 & 0\end{pmatrix}\) \(a_{11}=C_{11}=\begin{vmatrix}0 & -5 \\ 5 & 0\end{vmatrix}=0 - (-25)=25\)…