Question

A parabola can be drawn given a focus of (1, 10) and a directrix of

y = 4. What can be said about the parabola?

Answer 1

The parabola has an absolute minimum and its vertex is located at (1, 7).

Explanation:

Since the directrix is below the focus, we infer that parabola has an absolute minimum, where there is a vertex, which is the midpoint of the line segment between (1, 10) and (1, 4). By definition of midpoint, we conclude that vertex is located at (1, 7).