-12x2 +4x +8 = 0
ax2 bx c = 0
a = -12
b = 4
c = 8
Δ = b2-4ac
Δ = 4² - (4 * -12 * 8)
Δ = 16 - (4*-96)
Δ = 16 - (-384)
Δ = 400 Δ > 0
-12x2+4x+8=0
x = -b ∓ √Δ 2a
x' = -4 - √400 2*-12 = -4 - 20.0 -24 = -24.0 -24 = 1.0
x" = -4 + √400 2*-12 = -4 + 20.0 -24 = 16.0 -24 = -0.666666666667
x' = 144.0
x" = -96.0
S = {x ∈ R / x' = 144.0, x" = -96.0 }