高二 数学 函数问题. 请详细解答,谢谢! (24 11:13:29)

f(x)=2cosx[sinxcos(π/3)+cosxsin(π/3)]-sin(π/3)
=2cosxsinxcos(π/3)+2cosx*cosxsin(π/3)-sin(π/3)
=sin2xcos(π/3)+(2cosx*cosx-1)sin(π/3)
=sin2xcos(π/3)+cos2xsin(π/3)
=sin(2x+π/3)