math tutorials translated into Python.

[PPaye]

This Pull request:

Translates all "math" tutorials into Python.

Changes or fixes:

It shows creative ways of using C++ methods in Python more than the usual way of ROOT.gROOT.ProcessLine method. There are some notes about why we should or shouldn't use some syntax(inherited from C++-ROOT) in Python. Enjoy them as much as I did reproducing them.

Checklist:

• [yes] very well tested changes locally
• [yes] updated the docs (if necessary)