Name __________________________________________________ 27-1: What is a Function
Homework
Math 8
#1 - #2. Write a relation from the graph.
1.
4. Express this table as a mapping. State
the Domain and Range.
2.
x
y
-5
3
0
8
2
9
2
-1
5. Express this mapping as a graph..
3. Express this relation as a table.
{(-11, 1), (2, -9), (0, 0), (4, -4)}
5
-3
1
2
-6
0
-6
4
Make a function table of values for each function with the given input values.
6. y = 5x − 1 for
7. y = 1.7 x for
x = -4, x = 12, x = 0, and x = 0.5
x = 1.7, x = 5, x = -5, and x = 100
8. Critique the reasoning of others. Josie used the function y = 4 x to complete the table
below. Then she wrote these ordered pairs: (4, 1), (12, 3), (20, 5), (28, 7). Do you agree
with Josie’s work? Justify your reasoning.
x
y
1
4
3
12
5
20
Create a mapping for each of the following representations.
10. y = x + 2 for
9. {(1, 3), (1, 4), (1, 5)}
x = {0, 1, 2, 3, 4}
7
28
11.
x
y
1
2
3
5
5
3
7
2
12. Which of the above mappings in #9 - #11 is not a function? Explain.
13. Create two tables of at least four values to represent two relations, one that is a function
and one that is not.
14. Justify your answer from above using a mapping.
15. Make use of structure. Explain how you can identify from a table a relation that does
not represent a function.
16. Which relation represents a function? Justify your choice.
Table A
x
1
3
4
5
Table B
y
5
7
8
8
x
1
3
3
4
y
5
7
8
10
The inverse of any relation is obtained by switching the coordinates in each ordered pair of the
relation.
17. Determine whether the inverse of the relation {(4, 0); (5, 1); (6, 2), (6, 3)} is a function.
EXPLAIN.
18. Is the inverse of a function always, sometimes, or never a function? Give an example to
explain your reasoning.
Determine whether each relation is a function. EXPLAIN.
19. {(13, 5); (-4, 12); (6, 0); (13, 10)}
21. {(-1, 6); (4, 2); (2, 36); (1, 6)}
20.
22.
Make a table of 5 ordered pairs for each equation and graph.
• For #23-#24, use your own values.
• For #25-#26, use x-values of -2,-1,0,1,2
25. y = x2 + 1
23. x – y = 7
x
y
x
24. y = -3x + 1
26. y = x + 3
x
y
x
y
y