Nice one Christy. Thanks!

Just a bit of terminology here:

- MathJax is the JavaScript library that runs in your web browser to render the equations.
- DiscourseMath is the plugin that integrates it into the Discourse software itself.
- L
^{A}T_{E}X is the name of the language that you use in your posts to write equations.

To include an equation, put it in between dollar signs:

```
$i \hbar \frac{d}{d t}\vert\Psi(t)\rangle = \hat H\vert\Psi(t)\rangle$
```

Or alternatively you can put it in a block (and split it up for clarity) using double dollar signs on their own lines:

```
$$
i \hbar \frac{d}{d t}\vert\Psi(t)\rangle
=
\hat H\vert\Psi(t)\rangle
$$
```

This will centre the equation like so:

i \hbar \frac{d}{d t}\vert\Psi(t)\rangle
=
\hat H\vert\Psi(t)\rangle

There are a whole lot of L^{A}T_{E}X cheat sheets all over the web. This is one of the clearest that I found:

http://tug.ctan.org/info/undergradmath/undergradmath.pdf

There’s also a Stack Exchange site for questions and answers about it:

Incidentally, Wikipedia also uses L^{A}T_{E}X – if you want to cite a particularly common equation, you can always click “Edit” or “View source” on the Wiki page itself and copy and paste the markup from there.