Question

If $A$ is a non singular square matrix of order $3\times 3$, find $|adjA|$.

Answer 1

We know that

$\left|adjA\right|={\left|A\right|}^{n-1}$

where n is the under of matrix A

Here n = 3

$\begin{array}{c}\left|adjA\right|={\left|A\right|}^{3-1}\\ ={\left|A\right|}^2\end{array}$