Question

Gráfico da função y=-x² +6x - 8

Answer 1

.
y=-x² +6x-8

a=-1
b=6
c=-8

Δ=b²-4ac
Δ=6²-4(-1)(-8)
Δ=36-32
Δ=4

$x'= \frac{-6+2}{-2} = \frac{-4}{-2} =2 \\ \\ x"= \frac{-6-2}{-2} = \frac{-8}{-2} =4 \\ \\ \\ Xv=- \frac{b}{2a} = \frac{-6}{-2} =3 \\ \\ Yv=- \frac{\triangle}{4a} = \frac{-4}{-4} =1 \\ \\ V(3,1)$

  X  |   Y
4   |  0    raiz
3    | 1    V
2    | 0    raiz