Question

o vertice da funçao quadratica f(x)=x²-2x-8

Answer 1

Explicação passo-a-passo:

$\sf f(x)=x^2-2x-8$

• $\sf x_V=\dfrac{-b}{2a}$

$\sf x_V=\dfrac{-(-2)}{2\cdot1}$

$\sf x_V=\dfrac{2}{2}$

$\sf \red{x_V=1}$

• $\sf y_V=\dfrac{-\Delta}{4a}$

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

$\sf \Delta=4+32$

$\sf \Delta=36$

$\sf y_V=\dfrac{-36}{4\cdot1}$

$\sf y_V=\dfrac{-36}{4}$

$\sf \red{y_V=-9}$

O vértice é $\sf V(1,-9)$