-1x2 -3x +4 = 0
ax2 bx c = 0
a = -1
b = -3
c = 4
Δ = b2-4ac
Δ = -3² - (4 * -1 * 4)
Δ = 9 - (4*-4)
Δ = 9 - (-16)
Δ = 25 Δ > 0
-x2-3x+4=0
x = -b ∓ √Δ 2a
x' = 3 - √25 2*-1 = 3 - 5.0 -2 = -2.0 -2 = 1.0
x" = 3 + √25 2*-1 = 3 + 5.0 -2 = 8.0 -2 = -4.0
x' = 1.0
x" = -4.0
S = {x ∈ R / x' = 1.0, x" = -4.0 }