# Ellipse: Reflective Property

- Author:
- Tim Brzezinski

In the applet below, a tangent line is drawn to a point on an ellipse with foci

*F**and*_{1 }*F*_{2. }Interact with the following applet for a few minutes. As you do, be sure to change the locations of the LARGE POINTS each time before re-sliding the slider. Please answer the questions that appear below the applet.## 1.

How would you describe what you see here in your own words?

## 2.

How can we formally prove what is dynamically illustrated here?