将（2x-π/3）看成一个变量设为m
则f(x)=sinm+√3cosm=(√[(√3)^2+1^2])(1/2sinm+(√3)/2cosm)=2(sinmcos(π/3)+cosmsin(π/3))
=2sin(m+π/3)将m带入有
=2sin[(2x-π/3)+π/3]=2sin2x