Question

A alternativa que determina as raízes da função f(x) = x² + x - 12 é: * S={ -3, 3} S={- 4, 3} S={ 1, -2} S={ -1, 2}

Answer 1

Resposta:

S = {-4,3}

Explicação passo-a-passo:

x² + x - 12 = 0

a = 1

b = 1

c = -12

1)Calculamos o delta (Δ)

Δ= b² - 4ac

Δ = 1² - 4.1.(-12)

Δ= 1 + 48

Δ = 49

2)Calculamos o Baskhara

$x = \frac{-b \± \sqrt{delta} }{2a}\\ \\x1 = \frac{-1 + \sqrt{49} }{2.1}\\\\x1 = \frac{-1 + 7 }{2}\\\\x1 = \frac{6}{2}\\\\x1 = 3\\\\\\x2 = \frac{-1 - \sqrt{49} }{2.1}\\\\x2 = \frac{-1 - 7 }{2}\\\\x2 = \frac{-8}{2}\\\\x2 = -4$