Question

The equation of the parabola whose focus is at (0, 5) and directrix at y = -5 is:

Answer 1

For a parabola at vertex (0,0)
we see that we have to go up and down
therfor it opens up or down

since focus is above directix, it opens up
x^2=4Py
p is distance from directix to vertex
since it opens up, P is positive
from -5 to 0 is 5 units
x^2=4(5)y
x^2=20y
solve for y
divide both sides by 20
y=(1/20)x^2

first one