Mathematics · 2020
JEE Main · 6 September 2020, Shift 2 · Q54
Let θ=(π)/5 and A= [cos θ, sin θ; - sin θ, cos θ]. If B=A+A^4, then det (B):
Let $\displaystyle \theta=\frac{\pi}{5}$ and $\displaystyle A=\left[\begin{array}{ll}\cos \theta & \sin \theta \\ -\sin \theta & \cos \theta\end{array}\right]$. If $\displaystyle B=A+A^4$, then $\displaystyle \operatorname{det}(B)$ :
Official answer
(4)
lies in $\displaystyle (1, 2)$.
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JEE Main 2020 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.