Question

Someone check this?
Write an equation of a parabola that opens us, with vertex at the origin and the given focus.
(0,-5)
4p(y-k) = (x-h)2
4(-5)y = x^2
-20y = x^2
y = (1/-20) = x^2

Answer 1

@mathmate

Answer 2

@ganeshie8

Answer 3

It doesn't look right.
If the parabola opens up, the focus should be above the vertex at (0,5), for example.
Otherwise you work is correct.