FUNCTION OR NOT?
3.06
DETERMINE THE CHARACTERISTICS OF THE
RELATIONS GIVEN
Identify if each is:
Continuous or Discrete
Linear or Non-linear
If linear, identify the equation of the line
CHARACTERISTICS OF RELATIONS
Continuous or Discrete?
Discrete
Linear or Non-linear?
Linear
y = 2x + 3
Function or not?
Function
FUNCTION OR NOT?
Go back to each graph and determine if each
relation is a function or not a function.
VERTICAL LINE TEST
A visual way to determine if a relation is a function or not
Draw vertical lines for every x-value in the domain to see if they
cross the relation more than once.
If each line crosses the relation only once, it is a function.
WHAT IF I DON’T HAVE A GRAPH?
As a team, determine if each relation given is a function
without graphing the points.
Be creative and organized!
MAPPING
If you are not given a graph, there are many different ways to
organize your information to determine if you have a function or
not. One method is called mapping.
1) Write the domain in one oval and the range in another.
2) Draw lines to connect the x-values to their matching y-values
3) Determine if any x-values have more than one y-value
MAPPING
Relation A:
Relation B:
(-5, -2) (-1, -8) (9, -8) (4, 8)
(-5, -8) (4, 8) (-5, -2)
Function!
Not a function!
PRACTICE MAPPING
As a team, try the mapping method on your paper.
WHAT METHOD DO YOU PREFER?
Determine if the final two relations are functions or not.
Your justification can be in words, a map, a graph, or work
shown in any method that you would like.