一简谐振动的振动曲线如图所示,则振动方程为[ ()-|||-x/cm-|||-0 https:/img.zuoyebang.cc/zyb_a388334a0a276b9b27f31715e684793f.jpg/s-|||-1-|||--1-|||--2-|||-A. =0.02cos (dfrac (2pi )(3)t+dfrac (2pi )(3))-|||-B. =0.02cos (dfrac (2pi )(3)t-dfrac (2pi )(3))-|||-C. =0.02cos (dfrac (4pi )(3)t-dfrac (2pi )(3))-|||-D. =0.02cos (dfrac (4pi )(3)t+dfrac (2pi )(3))