If $A = \begin{bmatrix} k/2 & 0 & 0 \\ 0 & l/3 & 0 \\ 0 & 0 & m/4 \end{bmatrix}$ and $A^{-1} = \begin{bmatrix} 1/2 & 0 & 0 \\ 0 & 1/3 & 0 \\ 0 & 0 & 1/4 \end{bmatrix}$,then $k+l+m=$

If $A = \begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 1 \\ 0 & -2 & 4 \end{bmatrix}$ and $I = \begin{bmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{bmatrix}$,and $A^{-1} = \frac{1}{6}[A^2 + cA + dI]$ where $c, d \in R$,then the pair of values $(c, d)$ is:

Let $F(\alpha ) = \begin{bmatrix} \cos \alpha & -\sin \alpha & 0 \\ \sin \alpha & \cos \alpha & 0 \\ 0 & 0 & 1 \end{bmatrix}$,where $\alpha \in \mathbb{R}$. Then $[F(\alpha )]^{-1}$ is equal to

Using elementary transformations,find the inverse of the following matrix,if it exists: $\left[\begin{array}{cc}1 & 2 \\ 2 & -1\end{array}\right]$

If $A = \begin{bmatrix} 1 & 3 & -2 \\ -3 & 0 & -5 \\ 2 & 5 & 0 \end{bmatrix}$ and $A(\operatorname{adj} A) = K I$,then the value of $K$ is (where $I$ is the unit matrix of order $3$).

If $A = \begin{bmatrix} 2 & -3 \\ 5 & 4 \end{bmatrix}$,then $A^{-1} = $ . . . . . . .