Chapter 13 wave motion and sound Neglecting the subscript, we have equivalent expressions for sh wave equation D(, t=DM cosa(t-)+8i D(x,)=DCOS[2丌( T 2 D(, t)=DM cos[2(ft-)+l D(x,)=DCo(Ot-kx+如)Chapter 13 Wave Motion and Sound Neglecting the subscript p, we have equivalent expressions for SH wave equation: ( , ) cos[ ( ) ] M o v x D x t = D  t - + ( , ) cos[2 ( ) ] M o x T t D x t D   =  - + ( , ) cos[2 ( ) ] M o x D x t D f t   =  - + ( , ) cos( ) M o D x t = D t - k x + 