4 1 Slope Intercept Form Word Problems Goals
4 -1 Slope Intercept Form Word Problems Goals: Graph and interpret equations in slope-intercept form that model real life situations. Use a graphing calculator to graph linear equations. Eligible Content: A 1. 1. 2. 1. 1 / A 1. 1. 2. 1. 3 / A 1. 2. 1. 1. 1 / A 1. 2. 1 A 1. 2. 2 / A 1. 2. 2. 1. 3 / A 1. 2. 2. 1. 4
Vocabulary �Slope is rate of change �y-intercept is the beginning amount
The graph shows the number of cookies left on a plate after time has passed at a party. Find the slope and tell what it reveals about the situation. Find the y-intercept and tell what it reveals about the situation. Cookies Example #1 22 20 18 16 14 12 10 8 6 4 2 0 0 2 4 6 8 Time (in minutes) 10
Example #2 �The equation h = ½ t + 24 models changing river heights. h represents the height of the river (in feet) and t represents the time (in hours) since the flooding began. • What does the slope of the equation reveal about this situation? • What does the y-intercept of the equation reveal about this situation?
Example #3 �The equation s = 15 t + 25 models changing speeds of a car as it enters an expressway. s represents the speed of the car (in miles per hour) and t represents the time (in minutes). • What does the slope of the equation reveal about this situation? • What does the y-intercept of the equation reveal about this situation?
Using the calculator Equations must be in slope intercept form. �Press Y= button �Type in equation �Press GRAPH button �To change the x and y axes press WINDOW
Examples Graph each equation on your calculator: 1. y = 3 x + 4 2. y = -5 x + 7 3. 2 x + y = 8 4. 3 x – 2 y = 10
Examples from earlier Graph each of the word problems from earlier in class: �River: �Car: y = ½ x + 24 y = 15 x + 25
Homework �None
- Slides: 9