P1 = (-4, 0)
P2 = (2,0)
From the information given, we can conclude that this is a vertical parabola that opens downwards.
Also we can see that the vertex is not (0,0)
Equation
(x - h)^2 = 4p(y - k)
To find the equation I need three point, to form 3 equations.
The values that I need to find are: h, k and p