What is the equation of the parabola with a focus at (0, -5) and directrix y = 5.

Question

I don’t know got to get the equation please help

Answer 1

The equation of a parabola can be written y=a(x-h)²+k where (h,k) is the vertex. The focus is at (h,k+p) and the directrix line is y=k-p where ap=1/4.

So (0,-5)=(h,k+p) making h=0, -5=k+p and 5=k-p.

From this we get k=0 and p=-5, making a=-1/20.

The equation is y=-x²/20.

Answer 2

X^2=4(y-4)