f(x)=sin(2x+π/3)+sin(2x-π/3)+2cos^2x+1
=1/2sin2x+√3/2cos2x+1/2sin2x-√3/2cos2x+cos2x
=sin2x+cos2x
=√2sin(2x+π/4)
最小正周期T=π,
2kπ-π/2
f(x)=sin(2x+π/3)+sin(2x-π/3)+2cos^2x+1
=1/2sin2x+√3/2cos2x+1/2sin2x-√3/2cos2x+cos2x
=sin2x+cos2x
=√2sin(2x+π/4)
最小正周期T=π,
2kπ-π/2