-6x2 +8x +14 = 0
ax2 bx c = 0
a = -6
b = 8
c = 14
Δ = b2-4ac
Δ = 8² - (4 * -6 * 14)
Δ = 64 - (4*-84)
Δ = 64 - (-336)
Δ = 400 Δ > 0
-6x2+8x+14=0
x = -b ∓ √Δ 2a
x' = -8 - √400 2*-6 = -8 - 20.0 -12 = -28.0 -12 = 2.33333333333
x" = -8 + √400 2*-6 = -8 + 20.0 -12 = 12.0 -12 = -1.0
x' = 84.0
x" = -36.0
S = {x ∈ R / x' = 84.0, x" = -36.0 }