CUET Preparation Today
Let A be a non-singular square matrix of order 3 and $|adj\, A| = 5$ then $|A|$ is equal to |
$±\sqrt{5}$ 5 25 125 |
$±\sqrt{5}$ |
The correct answer is Option (1) → $±\sqrt{5}$ For a square matrix of order $n$, $|\text{adj}A| = |A|^{\,n-1}$ Given $n=3$ and $|\text{adj}A|=5$, $|A|^{\,3-1}=|A|^2=5$ $\Rightarrow |A|=\pm\sqrt{5}$ $|A|=\pm\sqrt{5}$ |
