-4x2 +5x +6 = 0
ax2 bx c = 0
a = -4
b = 5
c = 6
Δ = b2-4ac
Δ = 5² - (4 * -4 * 6)
Δ = 25 - (4*-24)
Δ = 25 - (-96)
Δ = 121 Δ > 0
-4x2+5x+6=0
x = -b ∓ √Δ 2a
x' = -5 - √121 2*-4 = -5 - 11.0 -8 = -16.0 -8 = 2.0
x" = -5 + √121 2*-4 = -5 + 11.0 -8 = 6.0 -8 = -0.75
x' = 32.0
x" = -12.0
S = {x ∈ R / x' = 32.0, x" = -12.0 }