Question

determine o zero da função, definida por:
f(x)=x2-8x+15​

Answer 1

x² - 8x + 15 = 0

fórmula de Bhaskara , sendo que  :

a=1,b=−8,c=15.

$\Delta &= b^2-4\cdot a \cdot c\\\\\Delta &= (-8)^2- 4\cdot 1\cdot 15 \\\\\Delta &= 64-60 \\\\\Delta &= 4 \\ \\x &= \dfrac{-b\pm\sqrt{\Delta}}{2\cdot a} \\\\x &= \dfrac{8\pm\sqrt{4}}{2\cdot 1} \\\\x &= \dfrac{8\pm 2}{2} \\\\x_1 &= \dfrac{8 + 2}{2} = \dfrac{10}{2} = 5\\\\x_2 &= \dfrac{8-2}{2} = \dfrac{6}{2} = 3$

S={(5,3)}