-1x2 -12x +13 = 0
ax2 bx c = 0
a = -1
b = -12
c = 13
Δ = b2-4ac
Δ = -12² - (4 * -1 * 13)
Δ = 144 - (4*-13)
Δ = 144 - (-52)
Δ = 196 Δ > 0
-x2-12x+13=0
x = -b ∓ √Δ 2a
x' = 12 - √196 2*-1 = 12 - 14.0 -2 = -2.0 -2 = 1.0
x" = 12 + √196 2*-1 = 12 + 14.0 -2 = 26.0 -2 = -13.0
x' = 1.0
x" = -13.0
S = {x ∈ R / x' = 1.0, x" = -13.0 }