If $ A= \begin{bmatrix}
\cos2\alpha & -\sin2\alpha\\
\sin2\alpha & \cos2\alpha\\
\end{bmatrix}$ and $A+A^{t}=I$. Find the value of $\alpha$. Here $I$ denotes the $2*2$ identity matrix
Answer & explanation
Correct answer: option 1
Solving the matrix equation $A+A^{t}=I$ we get $2\cos2\alpha=1$. Hence $\alpha=\pi/6$