1. Chapter 9: Quadratic Relations and Systems Section 9-3: Ellipses

2. Objectives: Given the equation of an ellipse: Sketch the graph Calculate the focal radii and plot the foci Check the sketch by computer graphics

3. Ellipse An ellipse is a curve on a plane surrounding two focal points such that a straight line drawn from one of the focal points to any point on the curve and then back to the other focal point has the same length for every point on the curve.

4. Graph of an Ellipse

5. X-Radius and Y-Radius If an ellipse has its major and minor axes parallel to the coordinate axes, then: The x-radius is the distance from the center to the ellipse in the x-direction. The y-radius is the distance from the center to the ellipse in the y-direction

6. Equation for an Ellipse

7. Example 1: Sketch the graph of:

8. HOMEWORKHOMEWORK p. 476 #1-15 odd