-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 = -12.0 -24 = 0.5
x" = 4 + √256 2*-12 = 4 + 16.0 -24 = 20.0 -24 = -0.833333333333
x' = 72.0
x" = -120.0
S = {x ∈ R / x' = 72.0, x" = -120.0 }