Section 3.1 Rectangular Coordinate System 195 Interpreting a Graph Example 1 Refer to Figure 3-1 and Table 3-1. a. For which month was the number of clients the greatest? b. How many clients were served in the first month (January)? c. Which month corresponds to 60 clients served? d. Between which two consecutive months did the number of clients decrease? e. Between which two consecutive months did the number of clients remain the same? Solution: a. Month 12 (December) corresponds to the highest point on the graph.This represents the greatest number of clients, 90. b. In month 1 (January), there were 55 clients served. c. Month 4 (April). d. The number of clients decreased between months 3 and 4 and between months 9 and 10. e. The number of clients remained the same between months 8 and 9. Skill Practice Refer to Figure 3-1 and Table 3-1. 1. How many clients were served in October? 2. Which month corresponds to 70 clients? 3. What is the difference between the number of clients in month 12 and month 1? 4. For which month was the number of clients the least? 7 6 5 4 3 2 321 1 2 3 Quadrant I Origin 0 Figure 3-2 7654 4 5 6 7 y-axis 1 1 2 3 4 5 6 7 Quadrant II Quadrant III Quadrant IV x-axis Answers 1. 74 clients 2. Month 5 (May) 3. 35 clients 4. Month 1 (January) 2. Plotting Points in a Rectangular Coordinate System The data in Table 3-1 represent a relationship between two variables—the month number and the number of clients. The graph in Figure 3-1 enables us to visualize this relationship. In picturing the relationship between two quantities, we often use a graph with two number lines drawn at right angles to each other (Figure 3-2). This forms a rectangular coordinate system.The horizontal line is called the x-axis, and the vertical line is called the y-axis.The point where the lines intersect is called the origin. On the x-axis, the numbers to the right of the origin are positive and the numbers to the left are negative. On the y-axis, the numbers above the origin are positive and the numbers below are negative.The x- and y-axes divide the graphing area into four regions called quadrants.
miller_beginning_intermediate_algebra_4e_ch1_3
To see the actual publication please follow the link above