1) f`= 2cosx*(cos x)`=2cos x*(-sin x)= -2cos x sin x=-sin2x
2)3*2sin x*(sin x)`+2= 3*2sin x*cos x+2=3sin 2x+2
f`=2(sin2x+1)*(sin 2x+1)`=2(sin 2x+1)*2cos 2x=2*2sin 2x*cos 2x+4cos 2x=2*sin4x+4cos2x
4) f`= 3*(cos2x+sin 2x)²*(cos2x+sin2x)`= 3*(cos2x+sin2x)²*(2cos2x-2sin2x)=
=6(cos2x+sin2x)²(cos2x-sin2x)