Use the power-reducing identities to write sin2xcos2x in terms of the first power of cosine?

1 Answer
Mar 13, 2018

sin2xcos2x=1cos(4x)8

Explanation:

sin2x=1cos(2x)2

cos2x=1+cos(2x)2

sin2xcos2x=(1+cos(2x))(1cos(2x))4=1cos2(2x)4

cos2(2x)=1+cos(4x)2

11+cos(4x)24=2(1+cos(4x))8=1cos(4x)8