How to write LaTeX in IPython Notebook?

IPython notebook uses MathJax to render LaTeX inside html/markdown. Just put your LaTeX math inside $$.

$$c = \sqrt{a^2 + b^2}$$

Or you can display LaTeX / Math output from Python, as seen towards the end of the notebook tour:

from IPython.display import display, Math, Latex
display(Math(r'F(k) = \int_{-\infty}^{\infty} f(x) e^{2\pi i k} dx'))

This came up in a search I was just doing, found a better solution with some more searching, IPython notebooks now have a %%latex magic that makes the whole cell Latex without the $$ wrapper for each line.

Refer notebook tour for Rich Display System