Loading MathJax Dynamically

gistfile1.js

(function () {
  var script = document.createElement("script");
  script.type = "text/javascript";
  script.src = "http://cdn.mathjax.org/mathjax/latest/MathJax.js";   // use the location of your MathJax

  var config = 'MathJax.Hub.Config({' +
                 'extensions: ["tex2jax.js"],' +
                 'jax: ["input/TeX","output/HTML-CSS"]' +
               '});' +
               'MathJax.Hub.Startup.onload();';

  if (window.opera) {script.innerHTML = config}
               else {script.text = config}

  document.getElementsByTagName("head")[0].appendChild(script);
})();

http://docs.mathjax.org/en/v1.0/dynamic.html