The image shows a parabola with focus and directrix (the -axis).

1. Write an equation that would allow you to test whether a particular point is on the parabola.
2. The equation you wrote defines the parabola, but it’s not in a very easy-to-read form. Rewrite the equation to be in vertex form: , where is the vertex.

Your teacher will give you a set of cards. Take turns with your partner to match a graph with an equation.

1. For each match that you find, explain to your partner how you know it’s a match.
2. For each match that your partner finds, listen carefully to the explanation. If you disagree, discuss your thinking and work to reach an agreement.