1. Notes - Coordinate Plane & Graphing Quiz
Graphing Functions with Ordered Pairs
Find four solutions of .
Choose four values for x. Then substitute each value into the equation to solve for y. There are many possible solutions. The solutions you find depend on which x values you choose.
Notes - Coordinate Plane & Graphing Quiz

3. Graphing Functions with Ordered Pairs
Choose four x values and substitute them into 3 2 1 x
(x, y) y
9 (0, 9)
7 (1, 7)
5 (2, 5)
3 (3, 3)
Sample Answer: (0, 9), (1, 7), (2, 5), and (3, 3)
If 0 is the input  9 is the output.
If 1 is the input  7 is the output.
If 2 is the input  5 is the output.
If 3 is the input  3 is the output. 3
Example 2-2a

5. Graphing Functions with Ordered Pairs
Graph by plotting ordered pairs.
First, find ordered pair solutions. 2 1 –1 x
(x, y) y
– (–1, –4)
– (0, –3)
– (1, –2)
– (2, –1)
Four solutions are (–1,–4), (0,–3), (1,–2), and (2,–1).
Example 2-3a

6. Coordinate Plane

8. Graphing Functions with Ordered Pairs
Plot these ordered pairs and draw a line through them.
Four solutions are (–1,–4), (0,–3), (1,–2), and (2,–1).
Plot 2 points.
Now, draw a straight line between the points
Extend your line well beyond the two points.
Finally, check either of your last two points.
Is it on your line?
Then, you’ve graphed correctly!
Example 2-3a

10. Graphing Functions with Ordered Pairs
Graph y = 5 – x by plotting ordered pairs.
Answer:
Example 2-3b

11. Graphing Functions with xy Intercepts
1. State the x-intercept and the y-intercept of the line.
The graph crosses the x-axis at (–2, 0). The x-intercept is –2. The graph crosses the y-axis at (0, –2). The y-intercept is –2.
Answer: –2; –2
2. State the x-intercept and the y-intercept of the line.
The graph does not cross the x-axis. There is no x-intercept. The graph crosses the y-axis at (0, 2). The y-intercept is 2.
Answer: none; 2

12. Graphing Functions with xy Intercepts
State the x-intercept and the y-intercept of each line. 3. 4.
Answer: 1; 3
Answer: –1; none
Example 3-1b

13. Graphing Functions with xy Intercepts
5.Find the x-intercept and the y-intercept for the graph of . .
To find the x-intercept, let
Write the equation.
Replace y with 0.
Simplify.
The x-intercept is 4. So, the graph crosses the x-axis at (4, 0).

14. Graphing Functions with xy Intercepts
5. To find the y-intercept, let .
Write the equation.
Replace x with 0.
Simplify.
Divide each side by 2.
The y-intercept is 2. So, the graph crosses the y-axis at (0, 2).
Answer: x-intercept, 4; y-intercept, 2
Example 3-2a

15. Graphing Functions with xy Intercepts
7. Graph using the x- and y-intercepts.
Step 1 Find the x-intercept.
Write the equation.
Replace y with 0.
The x-intercept is 2, so the graph passes through (2, 0).
Add 6 to each side.
Divide each side by 3.
Step 2 Find the y-intercept.
Write the equation.
Replace x with 0.
The y-intercept is –6, so the graph passes through (0, –6).
Simplify.

16. Graphing Functions with xy Intercepts
7. The x-intercept is 2. So, the graph crosses the x-axis at (2, 0).
The y-intercept is –6, so the graph passes through (0, –6).
Draw your line.
Check Choose some other point on the line and determine whether its ordered pair is a solution of
Example 3-3a

18. Graphing Functions with xy Intercepts
8. Graph using the x- and y-intercepts.
Answer:
Example 3-3b

19. Graphing Functions with xy Intercepts
9. Mrs. Jones has $300 for home repairs. A plumber charges her $50 an hour. The equation represents the amount of money left in her budget after x number of plumbing hours. Use the intercepts to graph the equation.
Step 1 Find the x-intercept.
9. Step 2 Find the y-intercept.
Write the equation.
Write the equation.
Replace y with 0.
Replace x with 0.
Subtract 300 from each side.
The y-intercept is 300.
Divide each side by –50.
Reread the problem. Since the x-intercept is 6, what does that actually mean?
The y-intercept is What does that actually mean?
The x-intercept is 6.
Example 3-4a

20. Graphing Functions with xy Intercepts
9. Answer:
Describe what the intercepts mean.
Answer: The y-intercept shows how much money Mrs. Jones has in her budget before any work is done. The x-intercept means that she can afford only 6 hours of plumbing repair.
(0, 300)
(6, 0)

21. Graphing Functions with xy Intercepts
10. Suzanne has $125 to spend on new shoes. The shoe store is having a sale in which every pair of shoes is priced at $25. The equation represents the amount of money Suzanne has left after purchasing x pairs of shoes.
Use the intercepts to graph the equation.
Answer:
10. Describe what the intercepts mean.
Answer: The y-intercept shows how much money Suzanne has before buying any shoes. The x-intercept means that she can afford only 5 pairs of shoes.
Example 3-4b

22. Graphing Functions with xy Intercepts
11.
Graph using the x- and y-intercepts.
Note that is the same as
The y-intercept is –4, and there is no x-intercept.
Answer:
Example 3-5a

23. Graphing Functions with xy Intercepts
12.
Graph using the x- and y-intercepts.
Note that is the same as
The x-intercept is 5, and there is no y-intercept.
Answer:
Example 3-5a

24. Graphing Functions with xy Intercepts
Graph each equation using the x- and y-intercepts.
Answer:
Answer:
Example 3-5b

25. Make Your Own Function Rewrite your data in set notation*
* Set notation lists data as ordered pairs.
* Example: { (2,8), (-8,7), (0,4) }
~ What is the independent variable?
~ Write only the domain of the data in set notation.
~ What is the dependent variable?
~ Write only the range of the data in set notation.
~ Does the data represent a function?
* Explain your answer. '

26. Make Your Own Function
Plot all ordered pairs, then connect each point from left to right.
~ When the line crosses the x-axis, what's the value of y?
~ What's the x-intercept?
~ When the line crosses the y-axis, what's the value of y?
~ What's the y-intercept?
~ What does the x-intercept mean?
~ What does the y-intercept mean?

27. Coordinate Plane

28. Coordinate Plane