2cos^2-1=cos2x
cos^2=(1+cos2x)/2
f(x)=sinxcosx-(根号3)cos^2+(根号3)/2
=sin2x/2-根号3*(cos2x+1)/2
=sin2x/2-根号3*/2*cos2x
=sin2xsin30-cos2xcos30
=-cos(2x+30)
=cos(2x-150)
1,最小正周期π
图像对称中心座标x=5π/12
2 当0＜=x＜=π／2时
fx值域[-√3/2,1]