-12x2 +4x +5 = 0
ax2 bx c = 0
a = -12
b = 4
c = 5
Δ = b2-4ac
Δ = 4² - (4 * -12 * 5)
Δ = 16 - (4*-60)
Δ = 16 - (-240)
Δ = 256 Δ > 0
-12x2+4x+5=0
x = -b ∓ √Δ 2a
x' = -4 - √256 2*-12 = -4 - 16.0 -24 = -20.0 -24 = 0.833333333333
x" = -4 + √256 2*-12 = -4 + 16.0 -24 = 12.0 -24 = -0.5
x' = 120.0
x" = -72.0
S = {x ∈ R / x' = 120.0, x" = -72.0 }