-4x2 -7x +11 = 0
ax2 bx c = 0
a = -4
b = -7
c = 11
Δ = b2-4ac
Δ = -7² - (4 * -4 * 11)
Δ = 49 - (4*-44)
Δ = 49 - (-176)
Δ = 225 Δ > 0
-4x2-7x+11=0
x = -b ∓ √Δ 2a
x' = 7 - √225 2*-4 = 7 - 15.0 -8 = -8.0 -8 = 1.0
x" = 7 + √225 2*-4 = 7 + 15.0 -8 = 22.0 -8 = -2.75
x' = 16.0
x" = -44.0
S = {x ∈ R / x' = 16.0, x" = -44.0 }