Question

Determine as raízes da equação X2-X-2=0

Answer 1

x² - x - 2 = 0
a = 1, b = - 1, c = - 2

Δ = b² - 4ac
Δ = (- 1)² - 4 . 1 . (- 2)
Δ = 1 + 8
Δ = 9 = 3²

x = (- b ± √Δ)/2a
x = (- (- 1) ± √3²)/2 . 1
x = (1 ± 3)/2

x' = (1 + 3)/2 = 4/2 = 2
x'' = (1 - 3)/2 = - 2/2 = - 1