# Parabolas Lesson 8 Episode 3 (Teachers)

### Reflecting Keoni and Sasha reflect on the similarities and differences between the equations for two parabolas that have the same p-values. One parabola has a vertex at (0, 0) while the other parabola has a vertex at (0, 7).

### Episode Supports Focus Questions

For use in a classroom, pause the video and ask these questions:

1. [Pause video at 0:40]. Where did the equation y = x2/12 come from?

2. [Pause video at 1:32]. Where is the –7 in the diagram? Can someone come show us where it is in the diagram?

Supporting Dialogue

Provide opportunities to revoice the mathematical ideas of others:

1. Revoice what Sasha and Keoni noticed about what is the same and what is different about the two equations.

2. Revoice what Sasha and Keoni said about why there is a –7 in the equation instead of a +7.  How about someone else? Revoice what Sasha and Keoni and saying.

Math Extensions

1. Use the GeoGebra applet to get a graph of a parabola with a p-value of 3 and a vertex at the point (0, 5). Use the method that Sasha and Keoni used in this episode to derive the equation of the parabola with a vertex at (0, 5).

2. Use the methods used in this episode to derive the equation of this new parabola.