If text{adj} begin{bmatrix} 1 & 0 & 2 -1 & 1 | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Let $A = \begin{bmatrix} 1 & 0 & 2 \ -1 & 1 & -2 \ 0 & 2 & 1 \end{bmatrix}$. The adjoint of a matrix is the transpose of its cofactor matrix, $\

Vedclass · Accepted Answer

$5$

Vedclass · Answer

(C) Let $A = \begin{bmatrix} 1 & 0 & 2 \ -1 & 1 & -2 \ 0 & 2 & 1 \end{bmatrix}$. The adjoint of a matrix is the transpose of its cofactor matrix, $	ext{adj}(A) = [C_{ij}]^T$.The cofactors are calculated as follows:$C_{11} = +\begin{vmatrix} 1 & -2 \ 2 & 1 \end{vmatrix} = 1 - (-4) = 5$$C_{12} = -\begin{vmatrix} -1 & -2 \ 0 & 1 \end{vmatrix} = -(-1 - 0) = 1$$C_{13} = +\begin{vmatrix} -1 & 1 \ 0 & 2 \end{vmatrix} = -2 - 0 = -2$$C_{21} = -\begin{vmatrix} 0 & 2 \ 2 & 1 \end{vmatrix} = -(0 - 4) = 4$$C_{22} = +\begin{vmatrix} 1 & 2 \ 0 & 1 \end{vmatrix} = 1 - 0 = 1$$C_{23} = -\begin{vmatrix} 1 & 0 \ 0 & 2 \end{vmatrix} = -(2 - 0) = -2$$C_{31} = +\begin{vmatrix} 0 & 2 \ 1 & -2 \end{vmatrix} = 0 - 2 = -2$$C_{32} = -\begin{vmatrix} 1 & 2 \ -1 & -2 \end{vmatrix} = -(-2 - (-2)) = 0$$C_{33} = +\begin{vmatrix} 1 & 0 \ -1 & 1 \end{vmatrix} = 1 - 0 = 1$Thus, $	ext{adj}(A) = \begin{bmatrix} C_{11} & C_{21} & C_{31} \ C_{12} & C_{22} & C_{32} \ C_{13} & C_{23} & C_{33} \end{bmatrix} = \begin{bmatrix} 5 & 4 & -2 \ 1 & 1 & 0 \ -2 & -2 & 1 \end{bmatrix}$.Comparing this with the given matrix, we get $m = 4$ and $n = 1$.Therefore, $m+n = 4+1 = 5$.

If $\text{adj} \begin{bmatrix} 1 & 0 & 2 \\ -1 & 1 & -2 \\ 0 & 2 & 1 \end{bmatrix} = \begin{bmatrix} 5 & m & -2 \\ 1 & 1 & 0 \\ -2 & -2 & n \end{bmatrix}$, then $m+n=$

Similar Questions

If $A = \begin{bmatrix} 3 & -3 & 4 \\ 2 & -3 & 4 \\ 0 & -1 & 1 \end{bmatrix}$,then $A^{-1} = $

If $A = \begin{bmatrix} 1 & a & 3 \\ 1 & 1 & 5 \\ 2 & 4 & 7 \end{bmatrix}$ and $A^{-1} = \begin{bmatrix} 13 & 2 & -7 \\ -3 & b & 2 \\ -2 & 0 & 1 \end{bmatrix}$,then the values of $a$ and $b$ are respectively

If $P$ and $Q$ are two invertible matrices of the same order,then $\operatorname{Adj}(QP)$ is equal to

Find the inverse of the matrix (if it exists): $\left[\begin{array}{cc}2 & -2 \\ 4 & 3\end{array}\right]$

If $A$ is a non-singular matrix, then $\operatorname{Adj}\left(A^{-1}\right)=$

Vedclass Test Series

Exam Paper Generator

Online Exam Module