bonsoir
f (x) = 2 ( x - 6 ) ( x - 2 )
1. f (x) = 2 ( x² - 2 x - 6 x + 12 ) = 2 x² - 16 x + 24
2 . f (x) = 2 x² - 16 x + 24
α = 16 /4 = 4
β = 2 *4² - 16*4 + 24 = 32 - 64 + 24 = - 8
f (x) = 2 ( x - 4 )² - 8
3. C ( 4) = - 8 ( calculé au dessus)
2 x² - 16 x + 24 = 24
2 x² - 16 x = 0
2 x ( x - 8 ) = 0
x = 0 ou 8
allez termine