bonjour
d 1 ( 0) = 1 et d 1 ( 1 ) = 3
( 3 - 1 ) / ( 1 - 0 ) = 2
donc coefficient directeur = 2
d ( 0) = 1 donc b = 1
d ( 1) = 2 x + 1
d 2 ( 0 ) = 3 et d 2 ( 1 ) = 0
( 0 - 3 ) / ( 1 - 0 ) = - 3 donc a = - 3
d 2 ( 0) = 3 donc b = 3
fonction = - 3 x + 3
d 3 ( 0) = - 1 et d 3 ( 6 ) = 2
( 2 + 1 ) / ( 6 - 0 ) = 3/6 = 1 /2 donc a = 1/2
d 3 ( 6) = 2
6 * 1/2 + b = 2
6/2 + b = 2
3 + b = 2
b = 2 - 3 = - 1
fonction = x /2 - 1
d 4 ( 0) = 4 et d 4 ( 2 ) = 3
( 3 - 4 ) / ( 2 - 0 ) = -1/2
d ( 0) = 4
0 * - 1 + b = 4 donc b = 4
fonction = - x /2+ 4
