y=1/2sincosx-√3/2sin^2x+√3/4=1/4sin2x-√3/4(1-cos2x)+√3/4=1/4sin2x+√3/4cos2x
=1/2sin(2x+π/3)
函数图像的对称轴方程是2x+π/3=kπ+π/2
即x=kπ/2+π/12 k为整数