-4x2 +9x -2 = 0
ax2 bx c = 0
a = -4
b = 9
c = -2
Δ = b2-4ac
Δ = 9² - (4 * -4 * -2)
Δ = 81 - (4*8)
Δ = 81 - (32)
Δ = 49 Δ > 0
-4x2+9x-2=0
x = -b ∓ √Δ 2a
x' = -9 - √49 2*-4 = -9 - 7.0 -8 = -16.0 -8 = 2.0
x" = -9 + √49 2*-4 = -9 + 7.0 -8 = -2.0 -8 = 0.25
x' = 32.0
x" = 4.0
S = {x ∈ R / x' = 32.0, x" = 4.0 }