# Laplace of plane wave

1. Jun 28, 2012

### xz5x

This is what I got for Nabla and Laplace of plane wave. I have problems when I try to write out it with x, y, z coordinates. Can somebody help me? Thanks!

http://img213.imageshack.us/img213/9532/85490316.jpg [Broken]

http://img528.imageshack.us/img528/6835/f41cab97f649df5431127b5.png [Broken]

Last edited by a moderator: May 6, 2017
2. Jun 28, 2012

### Muphrid

What problems do you have? You should get the same thing, just written in terms of the components of $k$ and $r$.

3. Jun 28, 2012

### xz5x

@Muphrid

I know the result, but I have problems with procedure. Can you write down this equation; or just the start? Thanks!

4. Jun 28, 2012

### Muphrid

What's $k \cdot r$ when written in terms of cartesian coordinates?

5. Jun 28, 2012

Yes.