Differentiate sin2xcos2x
By the multiple rule
Diff of A.B = diff of A × B + diff of B × A
So
Diff of sin2X = 2×cos 2x
Diff of cos²x = - 2cosx.sonx =-sin2x
So answer is
2cos 2x.cos²x-sin²2x
Prove that
[1/(sec²x-cos²x) + 1/(cosec²x-sin²x)] sin²x cos²x =
(1-sin²x cos²x)/(2+sin²x cos²x)