Question 624986
What is the equation of the parabola with a directrix at y = 4 and focus (0, -4)
Given info shows equation of a parabola that opens downwards with vertex at (0,0)
Its form: x^2=-4py
axis of symmetry: x=0 or y-axis
p=4 (distance from directrix or focus to vertex on the axis of symmetry)
4p=16
equation:x^2=-16y