Question

Which equation represents a parabola with the focus at (0, -1) and

Answer 1

Answer:

Step-by-step explanation:

The vertex is halfway between focus and directrix, at (0,0).

The equation has the form y = ax².

Focal length p = distance between focus and vertex = 1

p = 1/|4a|

1 = 1/|4a|

|a| = ¼

The focus lies below the vertex, so the parabola opens downwards and a<0.

y = -¼x²