Q.
$A$ is an involuntary matrix given by
$A = \begin{bmatrix}
0 & 1 & - 1 \\
4 & - 3 & 4 \\
3 & - 3 & 4
\end{bmatrix}$ , then the inverse of $\frac{A}{2}$ will be
A) $2A$
B) $\frac{A^{- 1}}{2}$
C) $\frac{A}{2}$
D) $A^{2}$
Explanation
(a)
$A$ is involuntary. Hence,
$A^{2} = I \Rightarrow A = A^{- 1}$
Also,
$(kA)^{- 1} = \frac{1}{k}(A)^{- 1}$
$\Rightarrow \left( \frac{1}{2}A \right)^{- 1} = 2(A)^{- 1} \Rightarrow 2A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.