y=sin2xcos2x Y=2sinx-cos2x y=3cos²x+cosxsinx+sin²x的最大值和最小值

1,y=(1/2)sin4x,最大值是1/2,最小值是-1/22,y=2sinx+(sinx)^2-1=(sinx+1)^2-2,最大值是(1+1)^2-2=2,最小值是(-1+1)^2-2=-23,y=2(cosx)^2+(1/2)sin2x+1=(1/2)(sinx)^2+cos2x+2=(√5/2)sin(2x+p)+2最大值是2+√5/2,最...