Using MathJax in https://cloud.sagemath.com

Create a Sage Worksheet.
Typeset math using markdown mode and mathjax.
Double click toggles showing the markdown code.
Or you can use the hide=False option.
You can use mathjax in chat.
In addition, you can use mathjax in html.
The show command in Sage use mathjax to display mathematical objects.
You can also set typeset_mode(true) to make all output get typeset by default.
You can get the tex for any displayed formula.
IPython also supports Mathjax in markdown cells.