bonjour
f (x) = - 2 x + 4
tu calcules 2 images
f ( 0) = 4
f ( 3) = - 6 + 4 = - 2
f (x) = 2 x /3
f ( 0 ) = 0
f ( 3) = 6/3 = 2
d ( 0 ) = - 3 et d ( 4) = - 2
( - 2 + 3 ) / ( 4 - 0 ) = 1/4
ax = x /4
d ( 4 ) = - 2
4/4 + b = - 2
b = - 2 - 1 = - 3
fonction = x/4 - 3
d'où f (0) = - 3
