To add math equations within your replies, topics or zaks, simply enclose LaTeX syntax within [math] [/math] tags. LaTeX is an extremely simple, yet useful, syntax that allows mathematicians to easily communicate with others. If you are not familiar with LaTeX, you can quickly get upto speed by glancing over the following guide:
http://www.math.utep.edu/temp/Epoch/nasaepoch/node51.html
To get a quick taste of LaTeX, observe how the following code is converted into beautiful mathematical equations: