Question: If $\mathrm{A}=\left[\begin{array}{ll}3 & -4 \\ 1 & -1\end{array}\right]$, show that $\left(\mathrm{A}+\mathrm{A}^{\prime}\right)$ is skew-symmetric.
Solution:
$\Rightarrow \mathrm{P}^{\prime}=\mathrm{P}$
Hence $A-A^{\prime}$ is a skew symmetric matrix.
