Mathematics · 2019
JEE Main · 9 January 2019, Shift 1 · Q64
If A= [cos θ, - sin θ; sin θ, cos θ], then the matrix A^-50 when θ=(π)/12, is equal to:
If $\displaystyle A=\left[\begin{array}{cc}\cos \theta & -\sin \theta \\ \sin \theta & \cos \theta\end{array}\right]$, then the matrix
$\displaystyle A^{-50}$ when $\displaystyle \theta=\frac{\pi}{12}$, is equal to :
Official answer
(1)
$\displaystyle \left[\begin{array}{cc}
\frac{\sqrt{3}}{2} & \frac{1}{2} \\
-\frac{1}{2} & \frac{\sqrt{3}}{2}
\end{array}\right]$
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.