Bonjour,
1-
f(1/3) = (1/3 - 1)/(1/3 + 3) =(-2/3)/(4/3) = (-2/3) x 3/4 = -1/2
2-
A, B et C n’appartiennent pas à la courbe et d lui appartient
3-
h≠0
f(-3+h) = (-3+h-1)/(-3+h+3) = (h-4)/h
f(-3-h) = (-3-h-1)/(-3-h+3) = (-h-4)/-h = -(h+4/-h = (h+4)/h
f(-3+h) + f(-3-h) = (h-4)/h + (h+4)/h = 2h/h = 2
