f(x)=1/2sin²x+cos²x+根号3/2sinxcosx=1/2+1/2cos^2 x+√3/2sinxcosx
=1/2+1/4(1+cos2x)+√3/4sin2x
=3/4+1/2sin(2x+π/6)
T=2π/2=π
令2kπ-π/2