Respostas

2014-07-09T16:35:08-03:00
A)
x² + 6x + 9 = 0
Delta = 6² - 4.1.9
Delta = 36 - 36
Delta = 0

x = - 6 + - √0 / 2
x = - 6 + - 0 / 2

x' e x'' = - 6 + 0 / 2 = - 6 / 2 = - 3

b)
x² + 2x - 3 = 0
Delta = 2² - 4.1.(- 3)
Delta = 4 + 12
Delta = 16,

x = - 2 + - √16 / 2
x = - 2 + - 4 / 2

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

x'' = - 2 - 4 / 2 = - 6 / 2 = - 3