sin(x+π/3)=sin(π/3)-sinxsinxcos（π/3）+cosxsin（π/3）=sin（π/3）-sinx1/2sinx+√3/2cosx=√3/2-sinx3/2sinx+√3/2cosx=√3/2√3/2sinx+1/2cosx=1/2sinxcos（π/6）+cosxsin（π/6）=1/2sin（x+π/6）=1/2x+...