i had try to follow the instruction below but don't know wehre to find <head> or <body> code so i can insert the code to.

Using the MathJax Content Delivery Network (CDN)Â¶

To use MathJax from our server, you need to do two things:

1.Link MathJax into the web pages that are to include mathematics.

2.Put mathematics into your web pages so that MathJax can display it.

You accomplish the first step by putting

<script type="text/javascript"

src="

http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">

</script>

into the <head> block of your document. (It can also go in the <body> if necessary, but the head is to be preferred.) This will load the latest version of MathJax from the distributed server, and configure it to recognize mathematics in both TeX and MathML notation, and ask it to generate its output using MathML if the browser supports that well enough, and otherwise use HTML-with-CSS to display the mathematics. This is one of the most general configurations, and should suffice for most peopleâ€™s needs. Other configurations are available, however, and you can also provide additional configuration parameters to taylor one of the configurations to your needs. More details can be found in the Loading and Configuring MathJax instructions.

The use of cdn.mathjax.org is governed by its terms of service, so be sure to read that before linking to the MathJax CDN server.

To see how to enter mathematics in your web pages, see Putting mathematics in a web page below.