If $A=\left[\begin{array}{lll}1 & 0 & 1 \ 2 & 1 & 0 \ 3 & 2 & 1\end{array} ight]$, then det $A$ is equal to

Question

If $A=\left[\begin{array}{lll}1 & 0 & 1 \ 2 & 1 & 0 \ 3 & 2 & 1\end{array}ight]$, then det $A$ is equal to

Aicharya · Accepted Answer

We have, $ \begin{aligned} |A| & =\left|\begin{array}{lll} 1 & 0 & 1 \ 2 & 1 & 0 \ 3 & 2 & 1 \end{array}ight|=1(1-0)+0+1(4-3) \ & =1+1=2 \end{aligned} $

If $A=\left[\begin{array}{lll}1 & 0 & 1 \\ 2 & 1 & 0 \\ 3 & 2 & 1\end{array}\right]$, then det $A$ is equal to

Solution