If $A=\begin{bmatrix}a&0&0\\0&a&0\\0&0&a\end{bmatrix}$, then the value of $|adj\, A|$, is
Answer & explanation
Correct answer: option 3
Since A is a diagonal matrix. Therefore,
$|A|=a×a×a=a^3$
Also,
$|adj\, A|=|A|^{3-1}$ $[∵ |adj\, A|=|A|^{n-1}]$
$⇒|adj\, A|=|A|^2=a^6$