Direction of propagation of wave

[aseem]

how to prove that a wave given as A.exp[i (wt - kx) ] is moving in positive x direction ?

similarly, how to prove that a wave given as A.exp[i (wt + kx) ] is moving in negative x direction ?

Thanks a lot

 

[grzz]

let y = Aexp[i(wt - kx)].

Consider a point with fixed displacement y. If t increases, x must increase also to keep y constant.

But in y = Aexp[i(wt + kx)] to keep y constant as time t increses then x must decrease.

 

[aseem]

thank you. i got it :)