-9x2 +17x +2 = 0
ax2 bx c = 0
a = -9
b = 17
c = 2
Δ = b2-4ac
Δ = 17² - (4 * -9 * 2)
Δ = 289 - (4*-18)
Δ = 289 - (-72)
Δ = 361 Δ > 0
-9x2+17x+2=0
x = -b ∓ √Δ 2a
x' = -17 - √361 2*-9 = -17 - 19.0 -18 = -36.0 -18 = 2.0
x" = -17 + √361 2*-9 = -17 + 19.0 -18 = 2.0 -18 = -0.111111111111
x' = 162.0
x" = -9.0
S = {x ∈ R / x' = 162.0, x" = -9.0 }