Question

Resolva as seguintes equações
x2-x-2=0

Answer 1

x² - x - 2 = 0

A= 1
B= - 1
C= -2

∆ = b² - 4ac

∆= (-1)² - 4 . 1 . (-2)
∆ = 1 + 8
∆ = 9

x = -b ± √∆ /2a

x = - (-1) ± √9 / 2 . 1
x = 1 ± 3 / 2

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

S={ 2, - 1}