-9x2 -12x +12 = 0
ax2 bx c = 0
a = -9
b = -12
c = 12
Δ = b2-4ac
Δ = -12² - (4 * -9 * 12)
Δ = 144 - (4*-108)
Δ = 144 - (-432)
Δ = 576 Δ > 0
-9x2-12x+12=0
x = -b ∓ √Δ 2a
x' = 12 - √576 2*-9 = 12 - 24.0 -18 = -12.0 -18 = 0.666666666667
x" = 12 + √576 2*-9 = 12 + 24.0 -18 = 36.0 -18 = -2.0
x' = 54.0
x" = -162.0
S = {x ∈ R / x' = 54.0, x" = -162.0 }