2sin^2x cos^2x =? bantu jawab ya

jika soal:
2(sinx)^2(cosx)^2
2sinxcosx * sinxcosx
sin2x * (1/2)sin2x
(1/2)(sin2x)^2
atau
(1/2)-(1/2)(cos2x)^2
atau
(1/2)((1-cos4x)/2)
(1/4)(1-cos4x)

jika soal:
2sin2xcos2x
sin4x.