JEE Advance - Mathematics (2022 - Paper 2 Online - No. 16)
following matrices is equal to $M^{2022} ?$
Explanation
$$A=\left(\begin{array}{cc}\frac{5}{2} & \frac{3}{2} \\ -\frac{3}{2} & -\frac{1}{2}\end{array}\right)$$
$$A^{2}=\left(\begin{array}{cc}4 & 3 \\ -3 & -2\end{array}\right)$$
$$A^{3}=\left(\begin{array}{cc}\frac{11}{2} & \frac{9}{2} \\ -\frac{9}{2} & -\frac{7}{2}\end{array}\right)$$
$$A^{4}=\left(\begin{array}{cc}7 & 6 \\ -6 & -5\end{array}\right)$$
and so on
$A^n=\left(\begin{array}{cc}\frac{3 n}{2}+1 & \frac{3 n}{2} \\ -\frac{3 n}{2} & -\frac{3 n}{2}+1\end{array}\right)$
Now
$$
\begin{aligned}
A^{2022} & =\left(\begin{array}{ll}
\frac{3 \times 2022}{2}+1 & \frac{3 \times 2022}{2} \\
\frac{-3 \times 2022}{2} & \frac{-3 \times 2022}{2}+1
\end{array}\right) \\\\
& =\left(\begin{array}{cc}
3034 & 3033 \\
-3033 & -3032
\end{array}\right)
\end{aligned}
$$
$\therefore$ Option $(\mathrm{A})$ is correct
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