Résoudre l'équation 2x au carre - x - 11 = 0

a = 2
b = -1
c = -11

delta = b² - 4 ac = 89
racine(delta) = 9,434

x1 = (-b+racine(delta))/2a = (1+racine(delta)) / (4) = 2,6085

x2 = (-b-racine(delta))/2a = (1-racine(delta)) / (4) = -2,1085

2x² - x - 11 = 0

Δ = b² - 4ac
Δ = (- 1)² - 4 x 2 x (- 11)
Δ = 1 + 88
Δ = 89
√Δ = √89

x₁ = [tex] \frac{1- \sqrt{89} }{2\times2} = \boxed{\frac{1- \sqrt{89} }{4} }[/tex]

x₂ = [tex] \frac{1+ \sqrt{89} }{2\times2} =\boxed{ \frac{1+ \sqrt{89} }{4}} [/tex]