用到的公式sin2x=2sinxcosxcos2x=cos^2(x)-sin^2(x)sin^2(x)+cos^2(x)=1a^2-b^2=(a+b)(a-b)1/4sin2x*sin4x-sin^8(x)+cos^8(x)=(1/4)*2sin^2(2x)cos2x-[sin^4(x)+cos^4(x)][sin^4(x)-cos^4(x)]=(1/2)sin^2(2x)(cos^2x...