Even and Odd Functions
A Function can be classified as Even, Odd or Neither. This classification can be
determined graphically or algebraically.
Graphical Interpretation -
Even Functions: Odd Functions:
Have a graph that is Have a graph that is
symmetric with respect symmetric with respect
to the Y-Axis. to the Origin.
Algebraic Test Substitute

in for everywhere in the function and analyze the
results of

by comparing it to the original function
Even Function:
is Even when, for each in the domain of
,


Odd Function:
is Odd when, for each in the domain of
,


Examples:
a.
  b.

 c.
  


 


 

 

 

 




  








Y-Axis acts like a mirror
Origin If you spin the picture upside down
about the Origin, the graph looks the same!
Origin
Even Function!
Odd Function!
Neither!
Even and Odd Functions - Practice Problems
A. Graphically determine whether the following functions are Even, Odd, or Neither
1. 2. 3.
B. Algebraically determine whether the following functions are Even, Odd, or Neither
1.
 
   
2.


3.
 
4.

   
5.

 
 
6.
 
7.
+ 4
8.
 
 
9.
10.

 
Answers:
Section A (Graphs) Section B (Algebra)
1. Odd 1. Neither
2. Neither 2. Even
3. Even 3. Odd
4. Neither
5. Even
6. Neither
7. Even
8. Even
9. Odd
10. Odd