How to determine the direction of propgation of a plane wave?

Rex_chaos

hi all,
Suppose there is a plane wave u=exp(-i k x), where k is a wavenumber. How to determine it's moving direction?

Rex_chaos	How to determine the direction of propgation of a plane wave? Tweet hi all, Suppose there is a plane wave u=exp(-i k x), where k is a wavenumber. How to determine it's moving direction?