## Tuesday, July 12, 2011

### MathJax in Blogger (II)

The new awesome way to include math in a website is MathJax. Until recently, one had to install MathJax in their own server in order to include math in their webpages. That changed a few weeks ago; you can now specify in your html code that the required script be loaded from MathJax's website.

To get MathJax to work in Blogger, just go to your Blogger account, click "Design" (top right of the page), and then "Edit HTML". After the first <head> you see, paste
<script src='http://cdn.mathjax.org/mathjax/latest/MathJax.js' type='text/javascript'>
MathJax.Hub.Config({
HTML: ["input/TeX","output/HTML-CSS"],
TeX: { extensions: ["AMSmath.js","AMSsymbols.js"],
equationNumbers: { autoNumber: "AMS" } },
extensions: ["tex2jax.js"],
jax: ["input/TeX","output/HTML-CSS"],
tex2jax: { inlineMath: [ ['$','$'], ["\$","\$"] ],
displayMath: [ ['$$','$$'], ["\$","\$"] ],
processEscapes: true },
"HTML-CSS": { availableFonts: ["TeX"],
linebreaks: { automatic: true } }
});
</script>

You're done! You can now use the usual $...$ or $...$ for inline equations, and $$...$$ or
$...$ for equations that are centered in their own line.

Time for an example:
$\cos^2\theta-\sin^2\theta=\cos 2\theta.$ The above script loads AMSmath and AMSsymbols so that the macros defined in these popular packages are available for use in your blog.

UPDATE: Equations can now be numbered and referred to. For example, in Newtonian gravity we have
\label{eq:gravt}
F=G\frac{mM}{r^2}.
Also,
\label{eq:gravo}
F=mg,
and so equations (\ref{eq:gravt}) and (\ref{eq:gravo}) lead to$g=G\frac{M}{r^2},$assuming the equivalence of inertial and gravitational mass.