y=sin2/3x+cos2x/3+cos2x/3*根号3/2-sin2x/3*1/2 =1/2sin2x/3+(根号3/2+1)cos2x/3=根号[1/4+(根号3/2+1)^2]sin(2x/3+@)其中最小正周期T=2Pai/(2/3)=3Pai故图像中相邻二对对称轴的距离是半个周期,即有T/2=3Pai/2...