enjosymath

Works now. Solution: menu sub-items need to be added and then dragged graphically into place as a sub-item of the parent menu item, so that it appears indented. That’s on the Appearance > Menus admin page.

Sry, here

All right, apparently you need to specify a config now. I ripped this from Math Stack Exchange (which is the way I want MathJax to work anyway…)

<script type="text/x-mathjax-config">
                MathJax.Hub.Config({"HTML-CSS": { preferredFont: "TeX", availableFonts: ["STIX","TeX"], linebreaks: { automatic:true }, EqnChunk: (MathJax.Hub.Browser.isMobile ? 10 : 50) },
                                    tex2jax: { inlineMath: [ ["$", "$"], ["\\\\(","\\\\)"] ], displayMath: [ ["$$","$$"], ["\\[", "\\]"] ], processEscapes: true, ignoreClass: "tex2jax_ignore|dno" },
                                    TeX: {  noUndefined: { attributes: { mathcolor: "red", mathbackground: "#FFEEEE", mathsize: "90%" } } },
                                    messageStyle: "none"
                });
            </script>            <script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML"></script>

Just paste that in your header.php per the above instructions on the MathJax platform-specific page for WP, and it should work (at least for a while).

All right. I haven’t tested yet, but there’s the MathJax help page for people installing on a certain platform (includes WP):
https://www.mathjax.org/docs/2.0/platforms/index.html#platforms