For a 1D plane wave written mathematically as(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\exp(i k x)[/tex]

where i is sqrt(-1). k is the wavenumber. In many textbook, it reads this wave is moving to the right while [tex]\exp(-i k x)[/tex] is moving to the left. It is quite confusing. How do you tell that?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How do you tell the moving direction of a wave?

**Physics Forums | Science Articles, Homework Help, Discussion**