Question

Determine as raízes das equações:

a) 2x² + x - 1 = 0

Answer 1

2x²+x-1 = 0
4x+x = 0+1
5x = 1
x = 1
   -----
      5
x = 5

Answer 2

2x² + x - 1 = 0

Δ = b² - 4*a*c

Δ = (1)² - 4*(2)*(-1)

Δ = 9


x' = [-b+√Δ] / (2*a)

x' = [-(1)+√9]/ 2*2

x' = 1/2


x'' = [-b-√Δ] / (2*a)

x'' = [-(1)-√9]/ 2*2

x'' = -1


S = {-1, 1/2}