# Math autocompletion in org mode

What is the easiest way to get autocompletion for math symbols when I write latex formulas between $$..$$ or $...$ in org-mode?

Could packages like company-math or ac-math be used in org-mode, for example? How should I configure them to use them in org-mode?

You could use LaTeX-math-mode from the AucTex package. This provides quick completion of common math macros like \alpha, \sum, \Sigma etc. Make sure the package is loaded with the following line in your .emacs:
(require 'latex)

And then from your org-mode buffer turn on latex-math-mode with M-x latex-math-mode. This provides shortcuts for a number of math symbols. You start by entering the backtick symbol "". The next key will add a LaTeX macro. For example, a inserts \alpha, C-_ inserts \inf, etc. The full list is available on the auctex reference card, and you can add your own shortcuts by customizing the variable LaTeX-math-list.
Entering two backticks in a row inserts a plain backtick. You can change the prefix key if you don't want to use the backtick - see the customization option LaTeX-math-abbrev-prefix`.