化简1/4sin2x*sin4x-sin^8x+cos^8x

来源：学生作业学帮网编辑：学帮网时间：2024/06/03 11:35:57

1/4sin2x*sin4x-sin^8x+cos^8x
=sinxcosxsin2xcos2x+(cos^4x+sin^4x)(cos^4x-sin^x)
=2sin^2xcos^2xcos2x+(cos^4x+sin^4x)(cos^2x-sin^2x)
=cos2x(sin^2x+cos^2x)^2
=cos2x