2. • A relation is a mapping, or
pairing, of input values with
output values.
 “Mapping Diagram”

3. • If any input maps to more than
one output, then it is not a
function.
• Is this a function? Why or why
not?

4. YES!
NO!

5. Tell if each represents a function:
x y

6. Relations and functions can also
be represented using:
a set of ordered pairs
a table
a graph
an equation

7. Is the relation a function?
Remember: each input (x) can
only have one unique output (y)
{(0, 2), (1, 2), (3, 1), (4, 5)}
{(-2, 4), (0, 3), (-2, 2), (-4, 1)}
YES!
NO!

8. Determine whether the relation
is a function:
{(2, 6), (3, 7), (4, 8), (3, 9)}
{(1, -3), (0, -4), (-1, -3), (-2, -2)}

9. Is the relation a function?
input -2 -1 0 0 1 2
output 3 4 5 6 7 8

10. Is the relation a function?
input output
2 5
4 3
6 3

11. • A graph is a
function if no
vertical line
crosses the
graph at more
than one point.

12. Determine whether each graph
represents a function.
YES! YES! NO!

13. Determine whether each graph
represents a function.