If $A =\begin{bmatrix}0&0&\sqrt{3}\\0&\sqrt{3}&0\\\sqrt{3}&0&0\end{bmatrix}$ then $|adj\, A|$ is equal to |
3 9 27 81 |
27 |
The correct answer is Option (3) → 27 $A=\begin{pmatrix} 0&0&\sqrt3\\ 0&\sqrt3&0\\ \sqrt3&0&0 \end{pmatrix}$ Compute determinant of $A$ $|A|=-\sqrt3\begin{vmatrix}0&\sqrt3\\ \sqrt3&0\end{vmatrix}$ $=-\sqrt3(0-3)$ $=3\sqrt3$ For a $3\times3$ matrix $|\text{adj}\,A|=|A|^{2}$ $=(3\sqrt3)^2$ $=27$ The value of $|\text{adj}\,A|$ is $27$. |