求y=2sin²x+(√3)sin2x+3的周期
y=(1-cos2x)+(√3)sin2x+3=(√3)sin2x-cos2x+4=2[(√3/2)sin2x-(1/2)cos2x]+4
=2[sin2xcos(π/6)-cos2xsin(π/6)]+4=2sin(2x-π/4)+4
故最小正周期T=2π/2=π.
而π＋kπ都是其周期,其中k∈Z.