What is the determinant of the matrix A=(cosθ−sinθsinθcosθ)A = \begin{pmatrix} \cos \theta & -\sin \theta \\ \sin \theta & \cos \theta \end{pmatrix}A=(cosθsinθ−sinθcosθ)?
111
−1-1−1
000
cos(2θ)\cos(2\theta)cos(2θ)