If A be a square matrix such that

Question:

If $A$ be a square matrix such that $|a d j A|=|A|^{2}$, then the order of $A$ is____________

Solution:

Given:

$A$ is a square matrix

$|\operatorname{adj} A|=|A|^{2}$

As we know,

$|\operatorname{adj} A|=|A|^{n-1}$, where $n$ is the order of $A$

$\Rightarrow|A|^{2}=|A|^{n-1}$

$\Rightarrow 2=n-1$

$\Rightarrow n=3$

Hence, the order of $A$ is $\underline{3}$.

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