是f(x)=cos(2x+2π/3)+2cos²x吗?
如果是,
f(x)=cos2xcos2π/3-sin2xsin2π/3+2cos²x
=-cos2x/2-√3sin2x/2+1+cos2x
=cos2x/2-√3sin2x/2+1
=sin(2x+5π/6)+1
∴T=2π/2=π
是f(x)=cos(2x+2π/3)+2cos²x吗?
如果是,
f(x)=cos2xcos2π/3-sin2xsin2π/3+2cos²x
=-cos2x/2-√3sin2x/2+1+cos2x
=cos2x/2-√3sin2x/2+1
=sin(2x+5π/6)+1
∴T=2π/2=π