Question

Seja a função: x ao quadrado+3x-2 calcule as raízes

Answer 1

Resolução:

x² + 3x - 2 = 0
Δ = b² - 4.a.c
Δ = (3)² - 4.1.(-2)
Δ = 9 + 8
Δ = 17

x = [-b ± √(Δ)]/2.a
x = [-3 ± √(17)]/2.1
x = [-3 ± √17]/2

x' = -3/2 - √17/2
x'' = -3 + √17/2

S = {-3/2 - √17/2, -3 + √17/2}

Answer 2

$x^2 + 3x - 2 = 0 \\ \\ x_{1\ y\ 2}= \dfrac{-b\pm \sqrt{b^2-4ac} }{2a}\qquad \qquad a=1\qquad b= 3\qquad c=-2 \\ \\ \\ x_{\ 1\ y\ 2}= \dfrac{-3\pm \sqrt{3^2-4(1)(-2)} }{2(1)} \\ \\ \\ x_{\ 1\ y\ 2}= \dfrac{-3\pm \sqrt{9+8} }{2}\\ \\ \\ x_{\ 1\ y\ 2}= \dfrac{-3\pm \sqrt{17} }{2}\\ \\ \\ x_{\ 1}= \dfrac{-3+\sqrt{17} }{2}\qquad \qquad x_2= \dfrac{-3-\sqrt{17} }{2} \\ \\ \\ x_{\ 1}=- \dfrac{3}{2} + \dfrac{\sqrt{17} }{2}\qquad \qquad x_2=- \dfrac{3}{2} - \dfrac{\sqrt{17} }{2}$