* Locate a hyperbolas vertices and foci.
* Write equations of hyperbolas in standard form.
* Graph hyperbolas centered at the origin.
* Graph hyperbolas not centered at the origin.
* Solve applied problems involving hyperbolas.
2. Concepts and Objectives
The objectives for this section are
Locate a hyperbolas vertices and foci.
Write equations of hyperbolas in standard form.
Graph hyperbolas centered at the origin.
Graph hyperbolas not centered at the origin.
Solve applied problems involving hyperbolas.
3. Hyperbolas
Hyperbolas have two disconnected branches. Each
branch approaches diagonal asymptotes.
Parts of a hyperbola:
Center
Vertices
Asymptotes
Hyperbola
4. Hyperbolas
The general equation of a hyperbola is
or
The hyperbola opens in whichever direction has the
positive term (x-direction if x is positive, y-direction if y
is positive).
The slope of the asymptotes is always .
The vertices are rx or ry from the center, whichever
term is positive. a is the positive term radius, b is the
negative term radius.
=
2
2
1
x y
x h y k
r r
+ =
2
2
1
x y
x h y k
r r
y
x
r
r
6. Hyperbolas
Example: Graph + + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( ) ( ) ( )
+
+ =
+ +
2
2 2 2
2 2
9 10 8 197
5 9 5
4 4 4 4
x x y y
Notice that the
negative sign has
been factored as
well!
Remember to
distribute the
negative sign!
7. Hyperbolas
Example: Graph + + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( ) ( ) ( )
+
+ =
+ +
2
2 2 2
2 2
9 10 8 197
5 9 5
4 4 4 4
x x y y
( ) ( )
+ =
2 2
9 6
4 4
5 3
x y
Notice that the
negative sign has
been factored as
well!
Remember to
distribute the
negative sign!
8. Hyperbolas
Example: Graph + + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( ) ( ) ( )
+
+ =
+ +
2
2 2 2
2 2
9 10 8 197
5 9 5
4 4 4 4
x x y y
( ) ( )
+
=
2 2
9 5 4 4 36
36 36 36
x y
Notice that the
negative sign has
been factored as
well!
Remember to
distribute the
negative sign!
9. Hyperbolas
Example: Graph + + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( ) ( ) ( )
+
+ =
+ +
2
2 2 2
2 2
9 10 8 197
5 9 5
4 4 4 4
x x y y
( ) ( )
+
=
2 2
9 5 4 4 36
36 36 36
x y
( ) ( )
+
+ =
2 2
5 4
1
4 9
x y
Notice that the
negative sign has
been factored as
well!
Remember to
distribute the
negative sign!
10. Hyperbolas
Example: Graph + + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( ) ( ) ( )
+
+ =
+ +
2
2 2 2
2 2
9 10 8 197
5 9 5
4 4 4 4
x x y y
( ) ( )
+
=
2 2
9 5 4 4 36
36 36 36
x y
( ) ( )
+
+ =
2 2
5 4
1
4 9
x y
( ) ( )
+
+ =
2 2
2 2
5 4
1
2 3
x y
Notice that the
negative sign has
been factored as
well!
Remember to
distribute the
negative sign!
12. Hyperbolas
Example: Graph
Center (5, 4)
opens in y-direction
rx = 2, ry = 3
vertices 3
+ + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( )
+
+ =
2 2
2 2
5 4
1
2 3
x y
13. Hyperbolas
Example: Graph
Center (5, 4)
opens in y-direction
rx = 2, ry = 3
vertices 3
slope of asymptotes:
+ + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( )
+
+ =
2 2
2 2
5 4
1
2 3
x y
3
2
14. Hyperbolas
Example: Graph
Center (5, 4)
opens in y-direction
rx = 2, ry = 3
vertices 3
slope of asymptotes:
+ + + =
2 2
9 4 90 32 197 0
x y x y
( ) ( )
+
+ =
2 2
2 2
5 4
1
2 3
x y
3
2
15. Focal Length
In an ellipse, the sum of the distances from a point on the
ellipse to the two foci is constant, but in a hyperbola, its
the difference between the distances that is constant.
To find the focal radius, we can use the Pythagorean
Theorem.
Notice that c > a for the
hyperbola. a
b
c
= +
2 2 2
c a b
16. Classwork
College Algebra 2e
8.2: 12-44 (4); 8.1: 32-56 (4); 7.8: 36-44 (4)
8.2 Classwork Check
Quiz 8.1