1.
If f(x)=2cos4x2sin4x3+sin22x3+2cos4x2sin4xsin22x2cos4x3+2sin4xsin22xf(x)=\begin{vmatrix} 2\cos^{4}x & 2\sin^{4}x & 3+\sin^{2}2x \\ 3+2\cos^{4}x & 2\sin^{4}x & \sin^{2}2x \\ 2\cos^{4}x & 3+2\sin^{4}x & \sin^{2}2x \end{vmatrix}, then 15f(0)\frac{1}{5}f'(0) is equal to: