To display mathematics, I use MathJax.
Here is some in-line equation \(z = \sqrt{x^2 + y^2}\) and some
displayed one:
\[\Pr(\boldsymbol{x}\vert\boldsymbol{y}) = \frac{\Pr(\boldsymbol{x},\boldsymbol{y}) }{\Pr(\boldsymbol{y})} \]
To obtain this, I simply modified the template (in: login > settings > edit template) with the following lines:
<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> </script>
inserted somewhere between the <head> and </head> tags. For a local installation, simply change the URL in the src field, for instance:
<script type="text/javascript" src="./MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> </script>