-1x2 +18x -17 = 0
ax2 bx c = 0
a = -1
b = 18
c = -17
Δ = b2-4ac
Δ = 18² - (4 * -1 * -17)
Δ = 324 - (4*17)
Δ = 324 - (68)
Δ = 256 Δ > 0
-x2+18x-17=0
x = -b ∓ √Δ 2a
x' = -18 - √256 2*-1 = -18 - 16.0 -2 = -34.0 -2 = 17.0
x" = -18 + √256 2*-1 = -18 + 16.0 -2 = -2.0 -2 = 1.0
x' = 17.0
x" = 1.0
S = {x ∈ R / x' = 17.0, x" = 1.0 }