Réponse :
bonjour
f (4) = - 3 et f ( - 4) = - 2
( -2 + 3 ) / ( - 4 - 4 ) = - 1 /8
ax = - 1/8
f (4) = - 3
4 * - 1/8 + b = - 3
⇔ - 4/8 + b = - 3
⇔ - 1/2 + b = - 3
⇔ b = - 3 + 0.5 = - 2.5
f (x) = - x /8 - 2.5
d'om f ( - 4 ) = - 4 * - 1/8 - 2.5 = 4/8 - 2.5 = 0.5 - 2.5 = - 2