Question

Qual dos valores abaixo são raiz do polinômio p(x)=- x² - 4x - 3 ?

Answer 1

Explicação passo-a-passo:

$p(x) = {x}^{2} - 4x - 3$

$0 = {x}^{2} - 4x - 3$

${x}^{2} - 4x - 3 = 0$

$x = \frac{ - ( - 4)± \sqrt{ {( - 4)}^{2} - 4 \times 1 \times ( - 3)} }{2 \times 1}$

$x = \frac{ - ( - 4)± \sqrt{ {( - 4)}^{2} - 4 \times ( - 3)} }{2 \times 1}$

$x = \frac{ - ( - 4)± \sqrt{ {( - 4)}^{2} - 4 \times ( - 3)} }{2}$

$x = \frac{4± \sqrt{ {( - 4)}^{2} - 4 \times (- 3) } }{2}$

$x = \frac{4± \sqrt{16 - 4 \times ( - 3)} }{2}$

$x = \frac{4± \sqrt{16 + 12} }{2}$

$x = \frac{4± \sqrt{28} }{2}$

$x = \frac{4±2 \sqrt{7} }{2}$

$x = \frac{4 + 2 \sqrt{7} }{2} \\ x = \frac{4 - 2 \sqrt{7} }{2}$

$x = 2 + \sqrt{7} \\ x = 2 - \sqrt{7}$

$x_{1} = 2 - \sqrt{7} \\ x_{2} = 2 + \sqrt{7}$

ATT:ARMANDO

04/09/20

12:00 AM