-6x2 +6x +12 = 0
ax2 bx c = 0
a = -6
b = 6
c = 12
Δ = b2-4ac
Δ = 6² - (4 * -6 * 12)
Δ = 36 - (4*-72)
Δ = 36 - (-288)
Δ = 324 Δ > 0
-6x2+6x+12=0
x = -b ∓ √Δ 2a
x' = -6 - √324 2*-6 = -6 - 18.0 -12 = -24.0 -12 = 2.0
x" = -6 + √324 2*-6 = -6 + 18.0 -12 = 12.0 -12 = -1.0
x' = 72.0
x" = -36.0
S = {x ∈ R / x' = 72.0, x" = -36.0 }