Practice Parabola (Focus-Directrix Definition) in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

A parabola is the set of all points equidistant from a fixed point (the focus) and a fixed line (the directrix).

Every point on a parabola is exactly the same distance from the focus as it is from the directrix line. This geometric property is why satellite dishes and flashlight reflectors are parabolicβ€”signals from the focus reflect off the curve in parallel lines.

Example 1

easy
Find the focus and directrix of the parabola y = \frac{1}{8}x^2.

Example 2

medium
Write the equation of a parabola with vertex at the origin, opening to the right, with focus at (3, 0).

Example 3

medium
Find the focus and directrix of the parabola y = \frac{1}{8}x^2.

Example 4

medium
Find the equation of the parabola with focus (0, -4) and directrix y = 4.

Example 5

hard
A parabola has vertex (2, -1) and focus (2, 3). Find its equation and the length of the latus rectum.