Question

Calcule os zeros da função F(x) = x² − 8x + 7 = 0

Answer 1

Explicação passo-a-passo:

$\sf x^2-8x+7=0$

$\sf \Delta=(-8)^2-4\cdot1\cdot7$

$\sf \Delta=64-28$

$\sf \Delta=36$

$\sf x=\dfrac{-(-8)\pm\sqrt{36}}{2\cdot1}=\dfrac{8\pm6}{2}$

$\sf x'=\dfrac{8+6}{2}~\rightarrow~x'=\dfrac{14}{2}~\rightarrow~x'=7$

$\sf x"=\dfrac{8-6}{2}~\rightarrow~x"=\dfrac{2}{2}~\rightarrow~x"=1$

Os zeros são 7 e 1