f(x)=sin^4x+cos^4x+sin^2xcos^2x/2-2sinxcosx=(sin²x+cos²x)²-3sin²xcos²x/2-2sinxcosx=1-3sin²2x/8-sin2x=-(3/8)(sin2x+4/3)²+5/3,显然,最小正周期为2π/2=π.当sin2x= -1时,f...