Source: http://www.cafepedagogique.net/communautes/MarcCourbot/Documents/-%20Premi%C3%A8re%20S%20-/Chapitre%2001%20-%20G%C3%89N%C3%89RALIT%C3%89S%20SUR%20LES%20FONCTIONS/1S%20-%20Chapitre%2001%20-%20CT.pdf