MathJax is now enabled for this site.  For example, here are the Lorenz's equations:

\begin{aligned} \dot{x} & = \sigma(y-x) \\ \dot{y} & = \rho x - y - xz \\ \dot{z} & = -\beta z + xy \end{aligned}

which is created by

\begin{aligned}
\dot{x} & = \sigma(y-x)\\
\dot{y} & = \rho x - y - xz\\
\dot{z} & = -\beta z + xy
\end{aligned}

To setup MathJaX with Joomla! is easy.

Just add the following lines before the </head> tag in the file index.php in the template directory; save & close, and you have it. 

<script>
MathJax = {
  tex: {
    inlineMath: [['$', '$'], ['\\(', '\\)']]
  },
  svg: {
    fontCache: 'global'
  }
};
</script>
<script type="text/javascript" id="MathJax-script" async
  src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js">
</script>

There are also commercial plug-ins available for Joomla!