title: Mathjax multi-line equation rendering issue
body: <p>I'm using MathJax to display math in a webpage. My MathJax code looks like this: </p>
  
  <pre><code>&lt;script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"&gt;&lt;/script&gt;
  
      &lt;script type="text/javascript"
      src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"&gt;
      &lt;/script&gt;
  
      &lt;script type="text/x-mathjax-config"&gt;
        MathJax.Hub.Config({
          tex2jax: { inlineMath: [ ['$','$'], ["\\(","\\)"] ],
           processEscapes: true
          }
        });
  &lt;/script&gt;
  </code></pre>
  
  <p>MathJax seems to work great, however I simply can't figure out how on earth to write multi-line equations. For example, this multi-line equation doesn't render properly. The entire equation is on one line instead of 3:</p>
  
  <pre><code>$$
  \begin{eqnarray} 
  y &amp;=&amp; x^4 + 4      \nonumber \\
    &amp;=&amp; (x^2+2)^2 -4x^2 \nonumber \\
    &amp;\le&amp;(x^2+2)^2    \nonumber
  \end{eqnarray} 
  $$
  </code></pre>