Question

Derive the equation of the parabola with a focus at (0, −4) and a directrix of y = 4

Answer 1

We are given with the focus coordinates of (0,-4) and a directrix equation of y=4,. we are asked for the equation of the parabola. The vertex of the parabola should lie in between the directrix and the focus. Hence, vertex should be at (0,0). the curve goes downwards. and the length of the latus rectum is 4. Hence the equation is x2=-16y