22x2 -9x -13 = 0
ax2 bx c = 0
a = 22
b = -9
c = -13
Δ = b2-4ac
Δ = -9² - (4 * 22 * -13)
Δ = 81 - (4*-286)
Δ = 81 - (-1144)
Δ = 1225 Δ > 0
22x2-9x-13=0
x = -b ∓ √Δ 2a
x' = 9 - √1225 2*22 = 9 - 35.0 44 = -26.0 44 = -0.590909090909
x" = 9 + √1225 2*22 = 9 + 35.0 44 = 44.0 44 = 1.0
x' = -286.0
x" = 484.0
S = {x ∈ R / x' = -286.0, x" = 484.0 }