一振幅為A、周期為T、波長為λ平面簡諧波沿x負向傳播,在x=λ處,t=T/4時振動相位為π,則此平面簡諧波的波動方程為:()
A.y.=Acos(2πt/T-2πx/λ-π) B.y=Acos(2πt/T+2πx/λ+π) C.y=Acos(2πt/T+2πx/λ-π) D.y=Acos(2πt/T-2πx/λ+π)
A.f(x,t)=Acos(ax+bt) B.f(x,t)=Acos(ax-bt) C.f(x,t)=Acosax·cosbt D.f(x,t)=Asinax·sinbt
A.y=Acos[w(t+1/u)+φ0] B.y=ACOS[w(t-1/u)+φ0] C.y=Acos[wt+1/u+φ0] D.y=Acos[wt-1/u+φ0]