There will be occasions when it would be useful to be able to include a statistical formula within a question, answer, or comment. How is this supported?
jsMath would be awesome as it could allow dynamic previewing of mathematics in questions and answers.
As a stopgap measure, you can use a service that compiles markup, such as TeX, to an image and then link the image into your Question or Answer. Here's a list of some such services taken from a blog post by my good friend Cameron see his blog post for side-by-side comparisons.
Codecogs: Delivers GIF or PNG
mathTeX: Delivers GIF or PNG
mimeTeX: An older version of mathTeX
Sitmo Equation Editor: Delivers PNG, possibly others
mathTran: Delivers PNG, possibly others
It seems StackExchange scrubs image links that pass script parameters- which is unfortunate as these services can't be used directly from a post. However, you can download the generated image and rehost using a site like TinyPic.
Latex support is now built-in. See this meta thread from math.SE: https://math.meta.stackexchange.com/questions/2/tex-math-markup-is-sorely-needed
I have made this answer CW in case you want to see what you have to do to get latex output.
A demo: $\alpha$
John Gietzen over at http://math.stackexchange.com has created a greasemonkey script which uses the Google Charts API to create images on the fly from latex. I have asked his permission to adapt it for our site. See his answer to this question: https://math.meta.stackexchange.com/questions/2/tex-math-markup-is-sorely-needed
Here is a demo of the script: $\alpha$
Ok, here is the script put together by John: http://userscripts.org/scripts/show/81977
Presently, I have it working for in firefox with greasemonkey installed. Apparently, it works in Chrome as well but I have not been able to get it to work. I will update this answer if I can resolve that issue.
Perhaps, we should start using tex + the above script. The advantage is that as and when we get tex support from the devs all our posts will look nice.
In fact, you should be looking into using MathJax instead of/as well as jsMath. It's written by the same people, recently had its first release, and is much more stable and flexible. Right now, however, it's actually a little slower than jsMath, but they anticipate improving this soon.
The only time I've had to implement something like this was with a Moodle site where we made use of mimetex although this appears to have been superseded by mathtex which I haven't used. NRich make extensive use of jsMath very successfully and it probably isn't going to be as much of a nightmare to get working as mimetex was.
In my opinion, a solution should be found that displays the equations immediately, not after some seconds. Therefore, I vote for JS in the previews, but compiled tex when questions and answers are displayed!
I have to note that MathML support is available in Firefox 4b2. And while syntax does seem quite cumbersome:
<math> <mi>x</mi> <mo>=</mo> <mfrac> <mrow> <mo>−</mo> <mi>b</mi> <mo>±</mo> <msqrt> <msup> <mi>b</mi> <mn>2</mn> </msup> <mo>−</mo> <mn>4</mn> <mo>⁢</mo> <mi>a</mi> <mo>⁢</mo> <mi>c</mi> </msqrt> </mrow> <mrow> <mn>2</mn> <mo>⁢</mo> <mi>a</mi> </mrow> </mfrac> </math>
It could be great if we could be allowed this tags.x = − b ± b 2 − 4 ⁢ a ⁢ c 2 ⁢ a