Respostas

2013-12-11T10:55:06-02:00
f(x)=x²  -  2x  -  3
Δ = b²-4ac
Δ = (-2)²-4.1.(-3)
Δ = 4 + 12
Δ = 16
x = (-b+/-√Δ)/2a
x = [-(-2)+/-√16)]/2.1
x = (2+/-4)/2
x' = (2+4)/2 --> x' = 6/2 --> x' = 3
x" = (2-4)/2 --> x" = -2/2 --> x" = -1
Vértice: 
xV = -b/2a = -(-2)/2.1 = 2/2 = 1
yV = -Δ/4a --> yv = -16/4.1 --> yV = -16/4 --> yV = -4

V = (1, -4)
(0,-2) e (2,-2), (-1,1) e (3,1) ...