Source: http://urbanmathproject.free.fr/seriousgamemathematique/serious_game_cours_de_mathematiques_PDF/Secondes/Fiche%20m%C3%A9thode%20-%20Exercice%20corrig%C3%A9%20-%20Choisir%20la%20forme%20la%20plus%20appropri%C3%A9e%20d'une%20fonction%20pour%20le%20calcul%20d'ant%C3%A9c%C3%A9dents%20-.pdf