ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2023

If \(a_{i j}\) represents the element of \(i^{\text {th }}\) row and \(j^{\text {th }}\) column and \(A_{i j}\) is the corresponding cofactor, then for the matrix \(A=\left[\begin{array}{ccc}1 & -1 & 0 \\ 2 & 0 & 1 \\ 3 & 4 & 2\end{array}\right]\) the value of \(a_{11} A_{21}+a_{12} A_{22}+a_{13} A_{23}\) is:

  1. A -3
  2. B 0
  3. C 3
  4. D 5
Verified Solution

Answer & Solution

Correct Answer

(B) 0

Step-by-step Solution

Detailed explanation

\(a_{11}=1, a_{12}=-1, a_{13}=0\) \(A_{21} = - \det \begin{vmatrix} -1 & 0 \\ 4 & 2 \end{vmatrix} = -((-1)(2) - (0)(4)) = 2\) \(A_{22} = \det \begin{vmatrix} 1 & 0 \\ 3 & 2 \end{vmatrix} = ((1)(2) - (0)(3)) = 2\)…