Respostas

  • Usuário do Brainly
2014-07-15T13:51:25-03:00
F(x)=x²-2x-3

x²-2x-3=0
Δ=b²-4ac
Δ=4+12
Δ=16
√Δ=4

x'= \frac{2+4}{2} = \frac{6}{2} =3

x"= \frac{2-4}{2} = \frac{-2}{2} =-1

S={-1,3}

Coordenadas do vértice

xv
= \frac{-b}{2a} = \frac{2}{2} =1

yv= \frac{-delta}{4a} = \frac{-16}{4} =-4

V(1,-4)

Im={y∈R/y≥-4}

Valor mínimo a>0
-Δ/4a=-4