1. 71. Ellipse.notebook April 30, 2013
9.4 Ellipses
Ellipse ­ the set of all points P in the plane such that the sum of the
distances from P to two fixed points is a given constant.

2. 71. Ellipse.notebook April 30, 2013
Longer side ­ major axis
Fixed points ­ foci
Standard form x2 y2
a2 b2+ = 1
a or b = half length of x or y
1. x2 y2
25 9
+ = 1 Maj axis __ Vertices of Maj __________
Min axis __ Vertices of Min __________
x
2 y
2
b
2 a
2+ = 1

3. 71. Ellipse.notebook April 30, 2013
2. Write the equation in standard form and graph the ellipse: 5x
2 + 2y
2 = 15.