y=cos(2x-π/3)=cos[-π/2+(2x+π/6)]=sin(2x+π/6)=sin[2(x+π/12)]
函数y=sin2x的图像向左平移π/12个单位得到y=sin[2(x+π/12)]图象
∴y=cos(2x-π/3)图像向右平移π/12个单位得到y=sin2x图象