18x2 +20x +2 = 0
ax2 bx c = 0
a = 18
b = 20
c = 2
Δ = b2-4ac
Δ = 20² - (4 * 18 * 2)
Δ = 400 - (4*36)
Δ = 400 - (144)
Δ = 256 Δ > 0
18x2+20x+2=0
x = -b ∓ √Δ 2a
x' = -20 - √256 2*18 = -20 - 16.0 36 = -36.0 36 = -1.0
x" = -20 + √256 2*18 = -20 + 16.0 36 = -4.0 36 = -0.111111111111
x' = -324.0
x" = -36.0
S = {x ∈ R / x' = -324.0, x" = -36.0 }