f(x)=根号2sin(x+π/4)
最小值是-根号2讲讲被=根号2(根号2sinx/2+根号2cosx/2)=根号2(sinx*cosπ/4+cosx*sinπ/4)=根号2sin(x+π/4)π是怎么来的cosπ/4不是等于根号2/2吗