y=sin²(x/2)-sin(x/2)cos(x/2) =(1-cosx)/2-(1/2)sinx =1-(1/2)(sinx+cosx) =1-(√2/2)sin(x+π/4)当sin(x+π/4)=-1时，y有最大值，y(max)=1+√2/2；当sin(x+π/4)=1时，y有最小值，y(min)=1-√2/2；祝你开心！希望能帮到你，如果不懂，请追问，祝学习进步！O(∩_∩)O
