-1x2 -2x +3 = 0
ax2 bx c = 0
a = -1
b = -2
c = 3
Δ = b2-4ac
Δ = -2² - (4 * -1 * 3)
Δ = 4 - (4*-3)
Δ = 4 - (-12)
Δ = 16 Δ > 0
-x2-2x+3=0
x = -b ∓ √Δ 2a
x' = 2 - √16 2*-1 = 2 - 4.0 -2 = -2.0 -2 = 1.0
x" = 2 + √16 2*-1 = 2 + 4.0 -2 = 6.0 -2 = -3.0
x' = 1.0
x" = -3.0
S = {x ∈ R / x' = 1.0, x" = -3.0 }