MAC 1114 Trigonometry
Chapter 9 notes
Section 9.1 The Ellipse
The four conic sections
Conics:
From General Form, To Identify Conics
One squared term: Parabola
Two squared term:
same
sign &
same
coefficient: Circle
same sign &
different
coefficient: Ellipse
different signs
(number value not important):
Hyperbola
xy term
Hyperbola
Circles:
General Form: Ax
2
+ By
2
+ Cx + Dy + E = 0
(where A & B are the same coefficient; A = B)
Standard Form: (x-h)
2
+ (y-k)
2
= r
2
or
+
= 1
Center: (h, k)
radius:
A circle is a special type of ellipse, where the major axis and the minor axis are equal. To graph a circle
find the exterior points by using the center and the radius.