(Or, since you are in the french region of Switzerland, perhaps I should say Salut!)
Welcome to the Math Help forums. We are glad you joined us.
These forums are an excellent resource: lots of good information and many knowledgeable members here. (And any time you can help out somebody else, all the better.)
It is a great place for the sharing of ideas. I am sure you will learn a lot here.
See you around the forums.