1.如图所示,有一平面简谐波沿x轴负方向传播,坐标原点O的振动规律为+y=Acos(ot+),则B点的振动方程为()
A . y = Acos ( @ at - + )
u
B . y = Acos @ ( t + )
C. y = Acos [ @ ( t - - ) + 9 ] + u
D .y = Acos [ @ ( t - - ) + 9 ] + u