bonjour
f ( 0) = 3 et f ( 1 ) = - 2
( - 2 - 3 ) / ( 1 - 0 ) = - 5
ax = - 5
coefficient directeur = - 5 et b = 3
f ( x) = - 5 x + 3
f ( 2) = - 10 + 3 = - 7
*****************************
f ( - 1 ) = - 2 et f ( 1 ) = - 4
( - 4 + 2 ) / ( 1 + 1 ) = - 2 /2 = - 1
ax= - x
coefficient = - 1
f ( - 1 ) = - 2
- 1 * - 1 + b = - 2
b = - 2 - 1 = - 3
f (x) = - x - 3
ordonnée = - 3
f (2) = - 2 - 3 = - 5
