Mathematics

Problem

When the determinant

\begin{vmatrix} \cos 2x & \sin^2 x & \cos 4x \\ \sin^2 x & \cos 2x & \cos^2 x \\ \cos 4x & \cos^2 x & \cos 2x \end{vmatrix}

is expanded in powers of

\sin x

, the constant term in the expression is a. 1 b. 0 c. -1 d. 2