y=2sin²x+2√3sinxcosx-2
=1-cos(2x)+√3sin(2x)-2
=2sin(2x-π/6) -1
最小正周期=2π/2=π
当sin(2x-π/6)=1时,y有最大值ymax=2-1=1
当sin(2x-π/6)=-1时,y有最小值ymin=-2-1=-3