bjr
g(x) = 2x² - 12x + 16
1) calcul du discriminant Δ pour trouver les racines (cours)
Δ = (-12)² - 4*2*16 = 144 - 128 = 16 = 4²
x' = (12 + 4) / 4 = 4
et
x'' = (12 - 4) / 4 = 2
2) forme factorisée = (x - 4) (x - 2) (cours)
3) g(x) = 2x² - 12x + 16
cours :
xs = 12 / 4 = 3
et g(3) = 2*3² - 12*3 + 16 = 18 - 36 + 16 = -2
S (3 ; -2)
