Author: SEG
Last saved by: MHE
Company: McGraw-Hill

Lesson 1-6

Example 1	Graph Ordered Pairs
Graph each ordered pair on a coordinate system.
a.	(2, 3)
								
	Step 1		Start at the origin.			
	Step 2		Since the x-coordinate is 2,	
			move 2 units to the right.
	Step 3		Since the y-coordinate is 3,
			move 3 units up.  Draw a dot.

b.	(0, 5)
	
	Step 1		Start at the origin.
	Step 2		Since the x-coordinate is 0,
			you will not need to move right.
	Step 3		Since the y-coordinate is 5,
			move 5 units up.  Draw a dot on the axis.

Example 2	Identify Ordered Pairs
Write the ordered pair that names each point.
a.	A
				
	Step 1		Start at the origin.		
	Step 2		Move right on the x-axis	
			to find the x-coordinate of
			point A, which is 4.
	Step 3		Move up the y-axis to find
			the y-coordinate, which is 1.

	The ordered pair for point A is (4, 1).                                     
                                                                                                           
b.	B

Step 1 		Start at the origin.
Step 2 	Move right on the x-axis to find the x-coordinate of point A, which is 2.
Step 3	Move up the y-axis to find the y-coordinate, which is 6.

      The ordered pair for point B is (2, 6).

Example 3	Relations as Tables and Graphs
Express the relation {(1, 4), (3, 0), (5, 2), (2, 3)} as a table and as a graph.  Then determine the domain and range.
					
x | y
1 | 4
3 | 0
5 | 2
2 | 3

The domain is {1, 3, 5, 2}, and the range is {4, 0, 2, 3}.

Example 4	Apply Relations
CAR RENTAL     A midsize sedan can be rented for $40 per day.  Suppose x represents the number of days.
a.	Make a table of ordered pairs in which the x-coordinate represents the number of days and the y-coordinate represents the rental cost for 1, 2, 3, and 4 days.

x | y | (x, y)
1 | 40 | (1, 40)
2 | 80 | (2, 80)
3 | 120 | (3, 120)
4 | 160 | (4, 160)
  
b.	Then graph the ordered pairs (days, total cost).

c.	Describe the graph.
The points appear to fall in a line.