The inverse of the matrix $\begin{bmatrix}5 & 11\\1 & 2\end{bmatrix}$ is : |
$\begin{bmatrix}-2 & 11\\1 & -5\end{bmatrix}$ $\begin{bmatrix}2 & -11\\-1 & 5\end{bmatrix}$ $\begin{bmatrix}5 & 1\\11 & 2\end{bmatrix}$ $\begin{bmatrix}5 & -1\\-11 & 2\end{bmatrix}$ |
$\begin{bmatrix}-2 & 11\\1 & -5\end{bmatrix}$ |
The correct answer is Option (1) → $\begin{bmatrix}-2 & 11\\1 & -5\end{bmatrix}$ $A=\begin{bmatrix}5 & 11\\1 & 2\end{bmatrix}$ $|A|=10-11=-1$ $adj\,A=\begin{bmatrix}2 & -11\\-1 & 5\end{bmatrix}⇒A^{-1}=\frac{adj\,A}{|A|}=(-1)\begin{bmatrix}2 & -11\\-1 & 5\end{bmatrix}$ $=\begin{bmatrix}-2 & 11\\1 & -5\end{bmatrix}$ |