Réponse :
bonsoir
f ( x )= ( 36 - 4 x²) / - 2 x + 6
1. ensemble de Def = R \ 3
2. f (x) = 0
36 - 4 x² = 0
( 6 - 2 x ) ( 6 + 2 x ) = 0
x = 3 ou - 3
A ( 1/3 ) = ( 36 - 4 ( 1/3)² / - 2 ( 1/3 + 6)
= 36 - 4 * 1/9 / - 2/3 + 6
= 36 - 4/9 / - 2/3 + 18/3
= 324/9 - 4/9 : 16/3
= 320/9 x 3/16 = 960/144 = 20/3 = 6.66666. donc ∉