Toggle MathJax to copy EdX equations to Anki

edx-mathjax.js

// Based on https://github.com/mathjax/mathjax-docs/wiki/Obtaining-the-original-TeX-from-a-rendered-page

function removeTypeset() {
  var HTML = MathJax.HTML, jax = MathJax.Hub.getAllJax();
  for (var i = 0, m = jax.length; i < m; i++) {
    var script = jax[i].SourceElement(), tex = jax[i].originalText;
    if (script.type.match(/display/)) {tex = "\\["+tex+"\\]"} else {tex = "\\("+tex+"\\)"}
    jax[i].Remove();
    var preview = script.previousSibling;
    if (preview && preview.className === "MathJax_Preview") {
      preview.parentNode.removeChild(preview);
    }
    preview = HTML.Element("span",{className:"MathJax_Preview"},[tex]);
    script.parentNode.insertBefore(preview,script);
  }
}

function showTypeset(show) {
  MathJax.Hub.Queue(show ? ["Reprocess",MathJax.Hub] : removeTypeset);
}

function on() {
  showTypeset(true);
}

function off() {
  showTypeset(false);
}

Should paste the code in the console and then run "off()" or "on()" as needed.

Would be cool to create a hotkey using Greasemonkey.