Algebra 1 1.7

Slide 1: 

1. Make a table for y = 2x + 3 with domain 0, 3, 6, and 9. 2. Write a rule for the function. ANSWER Bell Ringer Warm-Ups

Slide 2: 

1.7 Represent Functions as a Graph Goal Represent functions as graphs You can use a graph to represent a function In a given table, each corresponding pair of input and output values forms an ordered pair An ordered pair of numbers can be plotted as a point The x-coordinate is the input The y-coordinate is the output The horizontal axis is labeled with the input variable The vertical axis is labeled with the output variable

: 

Graph a function EXAMPLE 1 STEP 1 Make an input-output table. SOLUTION

: 

Graph a function EXAMPLE 1 STEP 2 Plot a point for each ordered pair (x, y).

Slide 5: 

GUIDED PRACTICE for Example 1 1. Graph the function y = 2x – 1 with domain 1, 2, 3, 4, and 5.

: 

Graph a function EXAMPLE 2 The table shows the average score s on the mathematics section of the Scholastic Aptitude Test (SAT) in the United States from 1997 to 2003 as a function of the time t in years since 1997. In the table, 0 corresponds to the year 1997, 1 corresponds to 1998, and so on. Graph the function. SAT Scores

: 

SOLUTION STEP 1 Choose a scale. The scale should allow you to plot all the points on a graph that is a reasonable size. EXAMPLE 2 Graph a function The s-values range from 511 to 519, so label the s-axis from 510 to 520 in increments of 2 units. The t-values range from 0 to 6, so label the t-axis from 0 to 6 in increments of 1 unit.

: 

STEP 2 Plot the points. EXAMPLE 2 Graph a function

Slide 9: 

EXAMPLE 2 GUIDED PRACTICE for Example 2

: 

Write a function rule for a graph EXAMPLE 3 Write a rule for the function represented by the graph. Identify the domain and the range of the function. SOLUTION STEP 1 Make a table for the graph.

: 

Write a function rule for a graph EXAMPLE 3 STEP 2 Find a relationship between the inputs and the outputs. Notice from the table that each output value is 1 more than the corresponding input value. STEP 3 Write a function rule that describes the relationship: y = x + 1. A rule for the function is y = x + 1. The domain of the function is 1, 2, 3, 4, and 5. The range is 2, 3, 4, 5, and 6. ANSWER

Slide 12: 

GUIDED PRACTICE for Example 3 Write a rule for the function represented by the graph. Identify the domain and the range of the function.

Slide 13: 

GUIDED PRACTICE for Example 3 Write a rule for the function represented by the graph. Identify the domain and the range of the function. 4.

: 

Analyze a graph EXAMPLE 4 The graph shows guitar sales (in millions of dollars) for a chain of music stores for the period 1999–2005. Identify the independent variable and the dependent variable. Describe how sales changed over the period and how you would expect sales in 2006 to compare to sales in 2005. Guitar Sales

: 

Analyze a graph EXAMPLE 4 SOLUTION The independent variable is the number of years since 1999. The dependent variable is the sales (in millions of dollars). The graph shows that sales were increasing. If the trend continued, sales would be greater in 2006 than in 2005.

: 

EXAMPLE 4 GUIDED PRACTICE for Example 4

Slide 17: 

Homework Pages 46-48 Skills Practice # 1, 2, 4-13, 15-19, 21, 22