<p>The quantum wavefunction of a particle in a 2D box of dimensions L<sub>x</sub> and L<sub>y</sub>. The wavenumbers are:
</p>
<ul><li><i>n<sub>x</sub></i>=2</li>
<li><i>n<sub>y</sub></i>=1</li></ul>
<a href="//commons.wikimedia.org/wiki/User:Inductiveload" title="User:Inductiveload">Inductiveload</a>
Own drawing, plotted in MuPad.