Precalculus Chapter 1 Linear Functions and Their Graphs Prange, T. Iverson, Zurek 1 Blank Page 2 Chapter. Section. Target# Learning Target 1.1.1 I can find the slope given two points. 1.1.2 I can find the slope given an equation of a line. Practice for the Learning Target Score on Learning Target Quiz Help needed? yes/no Pg 11 7 (slope only), 9 (slope only) Pg 12 19a, 20a Pg 11 5 (identify the y-intercept), 6 (identify the yintercept), 23a 1.1.3 I can determine the y-intercept from a graph or an equation of the line. 1.1.4 I can interpret what the slope, y-intercept, and x-intercept mean in a real life situation. 1.1 worksheets in this packet 1.1.5 I can write the equation of a line in pointslope form and slope-intercept form. Pg 12 25 (slope intercept form only), 33 (point slope form only) 1.1.6 I can write the equation of a parallel line. Pg 12 55a, 57a 1.1.7 I can write the equation of a perpendicular line. Pg 12 55b, 57b 1.1.8 I can write, and graph, the equation of vertical and horizontal lines. Pg 11-12 1b, 2a, 4d, 29, 31 1.1.9 I can write the equation of a line that models a real world situation. 1.1 worksheets in this packet 1.7.1 I can find the regression line equation given a set of points. Pg 77 7(part b-d), 12, 13, 14, 16 1.7.2 I can analyze, interpret, and predict using the regression line. Pg 77 12, 13, 14, 16 1.5.1 Given an equation written in function notation, I can evaluate the function algebraically. 1.5 worksheet in this packet 1.5.2 I can evaluate a function using the graph. 1.5 worksheet in this packet 3 Chapter. Section. Target# Learning Target 1.3.1 I can graph a linear piecewise function from an equation or scenario. 1.3.2 Given a piecewise function, I can find the value of y, algebraically. 1.3.3 I can write a piecewise function from a graph. Practice for the Learning Target Score on Learning Target Quiz Help needed? yes/no Pg 39 41, 45 Pg 83 65 Evaluate all three problems for f(1). Pg 39 41, 45 Pg 83 65 Evaluate all three problems for f(1). 1.3 worksheet in this packet Pg 38 11-16 Determine if the graph represents a function using the Vertical Line Test. 1.3.4 I can identify whether or not a graph represents a function. 1.3.5 I can identify the domain and range from a piecewise graph using interval notation. 1.3 worksheet in this packet 1.3.6 I can identify and describe increasing, decreasing, and constant intervals using interval notation. 1.3 worksheet in this packet Essential Questions for the chapter 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? 2. How can the collection, organization, interpretation, and display of data be used to answer questions? Essential Questions for the course 1. How is this similar or different from what I have done before? 2. What can I do to retain what I have learned? 3. Does my answer make sense? If not, what do I do? 4. Do I need help, and where do I go to find it? 5. How would a calculator make this problem easier to do? 6. How do I explain or justify my work to myself and others? 7. What is the given information and how do I use it? 4 SCORING RUBRIC A+ MASTERY (+) 100% I completely understand the strategy and mathematical operations to be used, and I used them or correctly. I did all of my calculations correctly. 4.0 My work shows what I did and what I was thinking while I worked the problem. The way I worked the problem makes sense and is easy for someone else to follow. I followed through with my strategy from beginning to end. My work was clear and organized. M92% or 3.7 MASTERY (-) I completely understand the strategy and mathematical operations to be used, but one minor error kept me completing the problem correctly. DM 85% or 3.4 DEVELOPING MASTERY I understand the strategy and mathematical operations to be used, but a few minor errors kept me from completing the problem correctly. My thought process was correct but one minor error kept me from getting the correct answer, BUT: o The way I worked the problem makes sense and is easy for someone else to follow. o I followed through with my strategy from beginning to end. o My work was clear and organized. I correctly understood the concept, but my work lacks a few minor elements that would have made my thought process easy for anyone to follow. My thought process was correct but a few minor errors kept me from getting the correct answer. BU 75% or 3 BASIC UNDERSTANDING I used mathematical operations and a strategy that I think works for most of the problem. IU 50% or 2 INCOMPLETE UNDERSTANDING I wasn’t sure which mathematical operations to use, and my plan didn’t work. NE 0% or 0 NO EVIDENCE I did not demonstrate any understanding of the concept. My work included an obvious conceptual mistake. Several elements need to be added for my work to be easy to follow. I know which operations I should have used, but couldn’t complete the problem. I’m not sure how much detail I need in order to help someone understand what I did. I made several significant calculation errors. I tried several things related to the learning target(s), but didn’t get anywhere. I was not able to reach an answer. I left the problem blank. I didn’t know how to begin. I don’t know what to write. I wrote down information not related to the learning target(s). 5 Blank Page 6 1.1 Warm Up(s) 7 Date _______ Notes: 1-1 Day 1 & 2 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.1.1 I can find the slope given two points. 1.1.2 I can find the slope given an equation of a line. 1.1.3 I can determine the y-intercept from a graph or from the equation of the line. 1.1.4 I can interpret what the slope, y-intercept and x-intercept mean in a real life situation. 1.1.5 I can write the equation of a line in point-slope form and slope-intercept form. 1.1.6 I can write the equation of a parallel line. 1.1.7 I can write the equation of a perpendicular line. 1.1.8 I can write, and graph, the equation of vertical and horizontal lines. Vocabulary Slope parallel line y-intercept perpendicular line x-intercept vertical line point slope form horizontal line What Do You Already Know? Choose the best answer that corresponds to each: _____ 1. Slope-Intercept Form _____ 2. Vertical Line _____ 3. Point-Slope Form _____ 4. Horizontal Line _____ 5. A line going through (3, -4) and where m is undefined _____ 6. The slope of a horizontal line Other Things To Know! 7. Slope formula for two points: 5 9. Simplify 0 slope intercept form A. x # B. y # C. y = -4 D. x = 3 E. ( y y1 ) m( x x1 ) F. y mx b G. zero H. undefined 8. Find the slope of the line that contains (-1,5) and (3,-4). 0 10. Simplify 5 11. What is the slope of a vertical line? Example 1) Find the slope, y-intercept, and sketch the graph of: -4x - 2y – 8 = 0 Steps: You try: a) x 3 y 12 0 b) 16 8 y 0 8 Example 2) Write the equation of the line containing (-2, 3) & (3, -7) in both forms. Point-Slope Form: Steps Slope-Intercept Form: You try: Write the equation of the line containing (-3, 1) & (5, 5) in both forms. Point-Slope Form: Slope-Intercept Form: Parallel Lines: Example 3) Find the point-slope equation of the line that passes through the point (2, -1) and is ∥ to 2𝑥 − 3𝑦 = 5. Steps: You Try: Find the slope-intercept form of the line that passes through the point (-3, 1) and is ∥ to 𝑥 + 𝑦 = 5. 9 Perpendicular Lines: Example 4) Find the point-slope equation of the line that passes through the point (2, -1) and is to 2𝑥 − 3𝑦 = 5. Steps: You Try: Find the slope-int. form of the line that passes through the point (-3, 1) and is to 𝑦 − 3 = −2𝑥. 10 Homework for 1.1 Day 1: pg. 11-12: 1b, 2a, 4d, 5 (identify the y-intercept), 6 (identify the y-intercept), 7 (slope only), 9 (slope only), 19a, 20a, 23a, 29, 31 Day 2: pg. 11-12: 25 (slope intercept form only), 33 (point slope form only), 55a, 57a, 55b, 57b (B.O.B. is wrong for 57b) 11 Continue the 1.1 Homework here 12 Date _______ Notes: 1-1 Application problems Day 1 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.1.9 I can write the equation of a line that models a real world situation. Example 1 A) Make a table of values for the linear function y = 2x + 1. B) Does the x-value depend on the y-value we input, or does the y-value depend on the x-value that we input? C) Write the ordered pairs from the table of values in the space below. D) Graph the ordered pairs and draw the line that represents the function. E) If this was the linear function that represents the growth of a dolphin, what other information would be important to know about our data? F) So if we were then told that the variable x = ___________________________ and the variable y = ________________________, what would the slope mean in the context of this problem? 13 G) What would the y – intercept mean? H) Would negative x – values make sense in this situation? I) What would be the growth per year if our data was: X 1 4 Y 5 10 Example 2 Find the indicated information for the following application problems: A) A climber is on a hike. After 2 hours he is at an altitude of 400 feet. After 6 hours, he is at an altitude of 700 feet. Determine the dependent and independent variables and write the ordered pairs. B) What is the average rate of change in altitude? C) A scuba diver is 30 feet below the surface of the water 10 seconds after she entered the water and 100 feet below the surface after 40 seconds. Write the ordered pairs and determine the scuba divers rate of change in depth. D) A person weighed 145 pounds in 1986 and 190 pounds in 2007. What was the rate of change in weight? 14 Homework for 1.1 Day 1 Application Problems 1. Over the last 50 years, the average temperature has increased by 2.5 degrees worldwide (I made this up). What is the rate of change in worldwide temperatures per year? 2. Michael started a savings account with $300. After 4 weeks, he had $350, and after 9 weeks he had $400. What is the rate of change of money in his savings account per week? 3. A plane left Chicago at 8:00 A.M. At 1:00 P.M., the plane landed in Los Angeles, which is 1500 miles away. What was the average speed of the plane, in miles per hour, for the trip? 4. After 30 baseball games, A-Rod had 25 hits. If after 100 games he had 80 hits, what is his average hits per game? For problems 5 – 8 it may be helpful to draw a picture: 5. When the dependent variable increases and the independent variable increases, the rate of change is (Positive, Negative, zero, undefined) circle one. 15 Continue the Homework for 1.1 Day 1 Application Problems 6. When the dependent variable stays the same as the independent variable increases, the rate of change is (Positive, Negative, zero, undefined) circle one. 7. When the dependent variable decreases when the independent variable increases, the rate of change is (Positive, Negative, zero, undefined) circle one. 8. When the dependent variable increases when the independent variable stays the same, the rate of change is (Positive, Negative, zero, undefined) circle one. 16 Date _______ Notes: 1-1 Application problems Day 2 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.1.9 I can write the equation of a line that models a real world situation. Use x = the number of years since 2000. Example 1 A) During 2002, Nike’s net sales were $9.0 billion, and in 2007 net sales were $11.5 billion. Write a linear equation giving the net sales y in terms of the year x. (Hint: Write two ordered pairs first.) B) Predict the net sales for the year 2022. C) Graph on your calculator. Verify your prediction in B was correct. D) If Sketchers net sales were 3.0 billion in 2002 and 10.5 billion in 2007, determine the equation of the linear function representing Sketchers’ net sales during this time. E) Using your calculator, graph this function on the same grid as the Nike function. In the context of this problem, explain what the y-intercept means for each function. F) If you were thinking about investing in one of these companies, which company would be more successful after four years assuming these trends continue? How about 15 years out? G) In what year were the net sales for the companies approximately equal? Explain in words, how you would determine the exact time this occurred. 17 Example 2 Your cell phone plan is $59.99 per month with $0.20 for each additional minute over 500 minutes. (Hint: How much would you pay if you used 500 minutes?) A) What would the y-intercept be if we are only interested in graphing the minutes exceeding 500. B) Write a linear equation that will compute your monthly cost if you exceed the 500 minutes. C) How many minutes did you use for the whole month if your bill is $70.39 (note: no taxes/random fees) Example 3 A school district purchases a high-volume printer, copier, and scanner for $25,000. After 10 years, the equipment is expected to be worth $2000. A) Write a linear equation to represent the model. B) Find the value of the equipment after year 5. C) What is the x-intercept of this function and explain in words what that point represents. 18 Homework for 1.1 Day 2 Application Problems Use x = the number of years since 2000. 1. A librarian’s salary was $25,000 in 2000 and $27,500 in 2002. Determine two ordered pairs for this scenario. A. Assuming the librarian’s salary follows a linear growth pattern, find the slope of the line. B. Write the equation in slope intercept form. C. What will the librarian’s salary be in 2006? 2. The earnings per share of Harley-Davidson stock for in 2005 was $2.50 and in 2011 was $5.50. Find the equation in slope-intercept form that represents this situation. A. Interpret the meaning of the slope of the equation. B. What does the y-intercept indicate? 19 Continue the Homework for 1.1 Day 2 Application Problems 3. Pinemoor Pizza purchases a used pizza oven for $875 knowing that it will have to be replaced after 5 years (it will be worthless at this point). A. Write a linear equation for the value of the oven over the 5 year period. B. Angelo’s Pizza, across town, offers to buy the oven for $400. At this point Pinemoor has had the oven for three years. Prove algebraically why Pinemoor should sell the oven to Angelo’s. 4. Suppose the weight of an airplane (in pounds) is a linear function of the amount of fuel (in gallons) in its tank. When carrying 18 gallons of fuel, the airplane weighs 2217 pounds. When carrying 48 gallons of fuel, it weighs 2412 pounds. How much does the airplane weigh if it is carrying 60 gallons of fuel? 20 Date _______ Notes: 1-1 Application problems Day 3 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.1.9 I can write the equation of a line that models a real world situation. Model Problems A linear model is a linear equation that represents a real-world scenario. You can write the equation for a linear model in the same way you would write the slope-intercept equation of a line. The yintercept of a linear model is the quantity that does not depend on x. The slope is the quantity that changes at a constant rate as x changes. The change must be at a constant rate in order for the equation to be a linear model. Example 1 A machine salesperson earns a base salary of $40,000 plus a commission of $300 for every machine he sells. Write an equation that shows the total amount of income the salesperson earns, if he sells x machines in a year. The y-intercept is $40,000; the salesperson earns a $40,000 salary in a year and that amount does not depend on x. The slope is $300 because the salesperson’s income increases by $300 for each machine he sells. Answer: The linear model representing the salesperson’s total income is y = $300x + $40,000. Linear models can be used to solve problems. Example 2 The linear model that shows the total income for the salesperson in example 1 is y =300x + 40,000. (a) What would be the salesperson’s income if he sold 150 machines? (b) How many machines would the salesperson need to sell to earn a $100,000 income? (a) If the salesperson were to sell 150 machines, let x = 150 in the linear model; 300(150) + 40,000 = 85,000. Answer: His income would be $85,000. (b) To find the number of machines he needs to sell to earn a $100,000 income, let y = 100,000 and solve for x: y = 300x + 40,000 Write the linear model. 100,000 = 300x + 40,000 Substitute y = 100,000. 60,000 = 300x Subtract. x = 200 Divide. Answer: To earn a $100,000 income the salesperson would need to sell 200 machines. 21 You can also use the standard form to write a linear model. Use this form if you are analyzing two quantities that increase at different rates. Example 3 At a school play, children’s tickets cost $3 each and adult tickets cost $7 each. The total amount of money earned from ticket sales equals $210. Write a linear model that relates the number of children’s tickets sold to the number of adult tickets sold. Let x = the number of children’s tickets sold and y = the number of adult tickets sold The amount of money earned from children’s tickets is 3x. The amount of money earned from adult tickets is 7y. The total amount of money earned from ticket sales is 3x + 7y, which is equal to $210. Answer: 3x + 7y = 210. Example 4 In Example 3, how many children’s tickets were sold if 24 adult tickets were sold? If 24 adult tickets were sold, y = 24. Substitute y = 24 into the linear model above: 3x + 7y = 210 3x + 7(24) = 210 3x + 168 = 210 3x = 42 x = 14 Write the linear model. Substitute y = 24. Simplify. Subtract. Divide. Answer: 14 children’s tickets were sold. 22 Homework for 1.1 Day 3 Application Problems 1. Lin is tracking the progress of her plant’s growth. Today the plant is 5 cm high. The plant grows 1.5 cm per day. a. Write a linear model that represents the height of the plant after d days. b. What will the height of the plant be after 20 days? 2. Mr. Thompson is on a diet. He currently weighs 260 pounds. He loses 4 pounds per month. a. Write a linear model that represents Mr. Thompson’s weight after m months. b. After how many months will Mr. Thompson reach his goal weight of 220 pounds? 3. Paul opens a savings account with $350. He saves $150 per month. Assume that he does not withdraw money or make any additional deposits. a. Write a linear model that represents the total amount of money Paul deposits into his account after m months. b. After how many months will Paul have more than $2,000? 4. The population of Bay Village is 35,000 today. Every year the population of Bay Village increases by 750 people. a. Write a linear model that represents the population of Bay Village x years from today. b. In approximately many years will the population of Bay Village exceed 50,000 people? 23 Homework for 1.1 Day 3 Application Problems 5. Conner has $25,000 in his bank account. Every month he spends $1,500. He does not add money to the account. a. Write a linear model that shows how much money will be in the account after x months. b. How much money will Conner have in his account after 8 months? 6. A cell phone plan costs $30 per month for unlimited calling plus $0.15 per text message. a. Write a linear model that represents the monthly cost of this cell phone plan if the user sends t text messages. b. If you send 200 text messages, how much would you pay according to this cell phone plan? 7. Ben walks at a rate of 3 miles per hour. He runs at a rate of 6 miles per hour. In one week, the combined distance that he walks and runs is 210 miles. a. Write a linear model that relates the number of hours that Ben walks to the number of hours Ben runs. b. Ben runs for 25 hours. For how many hours does he walk? 8. A salesperson receives a base salary of $35,000 and a commission of 10% of the total sales for the year. a. Write a linear model that shows the salesperson’s total income based on total sales of k dollars. 24 b. If the salesperson sells $250,000 worth of merchandise, what is her total income for the year, including her base salary? Continue the Homework for 1.1 Day 3 Application Problems 9. Amery has x books that weigh 2 pounds each and y books that weigh 3 pounds each. The total weight of his books is 60 pounds. a. Write a linear model that relates the number of 2 pound books to the number of 3 pound books Amery has. b. If Amery has 10 3-pound books, how many 2-pound books does he have? 10. Max sells lemonade for $2 per cup and candy for $1.50 per bar. He earns $425 selling lemonade and candy. a. Write a linear model that relates the number of cups of lemonade he sold to the number of bars of candy he sold. b. If Max sold 90 bars of candy, how many cups of lemonade did he sell? 25 Continue the Homework 1.1 Day 3 Application Challenge Problems 11. A bacteria population doubles every minute. Explain why this population growth cannot be modeled using a linear equation. ____________________________________________________________________________________ ____________________________________________________________________________________ __________________________________________________________________________________ 12. Kara used the linear model y = 20,000 + 0.3x to predict her total salary from achieving total sales of x. What is her base salary? What percent commission does she earn? ____________________________________________________________________________________ ____________________________________________________________________________________ 13. Correct the Error Question: The model 2x + 5y = 85 can be used to model how much money Tim spent on x sodas and y sandwiches. If he bought 15 sodas, how many sandwiches did he purchase? Solution: 2x + 5(15) = 85 2x + 75 = 85 2x = 10 or x = 2 Tim bought 2 sandwiches. What is the error? Explain how to solve the problem. ____________________________________________________________________________________ 26 ____________________________________________________________________________________ 1.7 Warm Up(s) 27 Date _______ Notes: 1-7 Day 1 & 2 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? 2. How can the collection, organization, interpretation, and display of data be used to answer questions? Learning Targets: 1.7.1 I can find the regression line equation given a set of points. 1.7.2 I can analyze, interpret, and predict using the regression line. Vocabulary regression line 28 29 Example 1 The table below lists the resting hear rate (in beats per minute) and ages of 12 members of an aerobics class. Age Resting Heart Rate A. 15 20 25 30 30 37 40 42 45 48 55 55 70 68 68 72 65 64 58 62 55 57 54 50 Define the independent and the dependent variables. B. Using a graphing calculator, make a scatter plot. C. Using a graphing calculator, determine the line of best fit for this data set. Round to the nearest thousandths place and write the equation. D. Graph the line in the same window as the scatter plot. E. Write the dimensions of an appropriate window to use for this scatter plot. X min Y min X max Y max X scale Y scale F. Interpret the y-intercept of the regression equation in the context of the problem. G. Use the linear regression equation to predict the resting heart rate of a 27-year old. H. Use the linear regression equation to predict the resting heart rate of a 45-year old. 30 Homework for 1.7 Day 2 Pg 77 7(part b-d only), 12, 13, 14, 16 31 1.7 Day 3 Linear Regression Activity Barbie Bungee Jump # of rubber bands Distance dropped (to the top head) 1 2 3 4 5 1. Complete the table. 2. What are the independent and independent variables? 3. Plot the points on the grid. 4. Find the equation of the regression line. 5. Give an interpretation of the slope. 6. Give an interpretation of the y-intercept. 7. Use the regression line to predict how far she would fall with 10 rubber bands. 8. Barbie wants to bungee jump off of a 215 inch platform. She is a real thrill seeker and wants to drop as close to the ground as safely as possible. How many rubber bands will she need? 32 1.5 Warm Up(s) 33 Date _______ Notes: 1.5 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.5.1 Given an equation written in function notation, I can evaluate the function algebraically. 1.5.2 I can evaluate a function using the graph. Vocabulary function notation Example 1: Given f ( x) x 2 x 3 and 𝑔(𝑥) = a) find f (4) . (𝑥+4)(𝑥−8) (𝑥+2) b) find g ( 3) . c) evaluate 𝑓(𝑥 − 1). Example 2 Evaluate the function using the graph. a) b) 𝑓(3) = c) 𝑝(0) = 𝑡(−1) = Example 3 Using function notation to help solve a real-world problem. You are helping to organize a field trip to Yellowstone National Park for your science class. After some careful planning, you have discovered two equations that can be used to calculate the cost of the trip. The cost of lodging is indicated by the equation: 𝐿(𝑥) = 1400 + 15𝑥 where x is the number of people who come along. Likewise, the daily meal cost can be described by the equation: 𝑀(𝑥) = 3(8 + 7𝑥) where x, again, represents the number of people who make the trip. Describe using complete sentences how you would calculate the total daily cost of the trip for 7 people, then go ahead and calculate the cost. 34 Homework 1.5 Worksheet Use the following functions for problems 1 – 4. f ( x) 5 x 2 4 x 1 1. Evaluate 𝑓 (2). g( x) 3 x 1 h( x ) 7 2x x 3 k ( x) 2 2. Find 𝑔(−3.5). 3. Determine the value of 𝑘 (3). 4. Explain why ℎ(3) is undefined. 5. Evaluate 𝑓(𝑥 + 2). 6. 7. 𝑓(3) = 8. 1 2x 𝑝(0) = 9. 𝑡(−1) = 𝑇(2) = 35 Quiz Review (Sections 1.1, 1.7 and 1.5) 1. Given the line 3𝑥 − 4𝑦 = 8 1.1.5 I can write the equation of a line in point-slope form and slope-intercept form. a) Put the equation in slope-intercept form. 1.1.2 I can find the slope given an equation of a line. b) Identify the slope of this line. 1.1.6 I can write the equation of a parallel line. c) Find the equation of the line passing through (2, -1) which is parallel to the original line. Write your answer in point-slope form. 1.1.7 I can write the equation of a perpendicular line. d) Find the equation of the line passing through (2, -1) which is perpendicular to the original line. Write your answer in slope-intercept form. 1.1.1 I can find the slope given two points. 1.1.3 I can determine the y-intercept from a graph or an equation of the line. 2. Find the slope and y-intercept of the line passing through (-3, -1) and (-2, -5). 1.1.2 I can find the slope given an equation of a line. 1.1.3 I can determine the y-intercept from a graph or an equation of the line. 3. Find the slope and y-intercept of the equation 3𝑥 = 4𝑦 − 7. 1.1.8 I can write, and graph, the equation of vertical and horizontal lines. 4. Write the equation of a line whose slope is zero and y-intercept is 37 36 Continue Quiz Review (Sections 1.1, 1.7, and 1.5) 1.1.1 I can find the slope given two points. 1.1.3 I can determine the y-intercept from a graph or an equation of the line. 5. Find the slope and y-intercept of the line. 6. Shelia’s Appliance Repair charges $25 to make a house call and an additional $12 an hour for time spent at the appointment site. 1.1.9 I can write the equation of a line that models a real world situation. a) Write an equation that represents the total cost you would expect to pay if Shelia cane to fix your leaky dishwasher? 1.1.4 I can interpret what the slope, y-intercept, and x-intercept mean in a real life situation. b) Identify the slope from your equation and explain what it means in the context of this problem. 1.1.4 I can interpret what the slope, y-intercept, and x-intercept mean in a real life situation. c) Identify the y-intercept from your equation and explain what it means in the context of this problem. 7) Justin, a linebacker for the University of Kansas Jayhawks, believes that eating M&Ms before the game causes him to get more tackles during the game. During his previous several games, Justin has taken the following data. Number of M&Ms Eaten 25 60 45 80 30 Number of Tackles 3 5 4 7 3 1.7.1 I can find the regression line equation given a set of points. a) Use your calculator to find a linear regression equation that represents this data. 1.7.2 I can analyze, interpret, and predict using the regression line. b) How many tackles should Justin expect to get if he eats 150 M&Ms. Assume you cannot have a fraction of a tackle. 37 Continue Quiz Review (Sections 1.1, 1.7, and 1.5) 1.5.1 Given an equation written in function notation, I can evaluate the function algebraically. 8) Given ℎ(𝑥) = 𝑥 2 + 2𝑥 and 𝑘(𝑥) = − |𝑥 + 3| − 7 a) find ℎ(6). b) find 𝑘(3). c) find ℎ(𝑥 − 1). d) find 𝑘 (5). 2 1.5.2 I can evaluate a function using the graph. 9) Evaluate each function using the graph. a) b) t(5) = c) g(-2) = f(3) = h(-1) = 38 Warm Up 1.3 Graph the following absolute value functions. Use a graphing utility to help you remember the translation patterns from AAT. 1) 𝑓(𝑥) = |𝑥| 3) 𝑔(𝑥) = −|𝑥 − 3| 2) 𝑡(𝑥) = |𝑥 + 2| 4) ℎ(𝑥) = |𝑥 + 5| − 2 Summarize the translations above. You will need to use them for the remainder of this packet. 39 Date _______ Notes: 1.3 Day 1 & 2 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Targets: 1.3.1 I can graph a linear piecewise function from an equation or scenario. 1.3.2 Given a piecewise function, I can find the value of y algebraically. 1.3.3 I can write a piecewise function from a graph. Vocabulary piecewise functions function function notation Definition of a Piecewise-Defined Function: Why? Example 1 Graph the following piecewise functions and evaluate the function at a given value. f ( x) 3 x x 0 a) f ( x) x 1 x 0 1 f ( x) x 2 x 2 3 b) f ( x) x 2 x 2 40 Example 2 Write a function that represents each scenario and graph it. (label axis and include scale) a) The parking lot charges $3 per hour for the initial 3 hours and $10 after this. b) Jacob was paid an hourly wage of $8 for 30 hours per week and an additional hourly wage of $12 for more than 30 hours. c) A copy shop charges $0.15 per photocopy for orders of 20 or fewer photocopies, $0.12 per photocopy for orders of 50 or fewer but more than 20 photocopies, and $0.10 per photocopy for orders of more than 50 photocopies. Write a function represents the cost C in dollars for x number of photocopies? d) A store charges $15 per t-shirt for orders of 50 or fewer T-shirts, $13.50 per t-shirt for orders of 75 or fewer but more than 50 t-shirts, and $12.50 per t-shirt for orders of more than 75 t-shirts. Which function best represents the printing cost C for x number of t-shirts? 41 Example 3 a) Draw a graph the shows a man climbing down a ladder that is 10 feet high. At time 0 seconds, his shoes are at 10 feet above the floor, and at time 6 seconds, his shoes are at 3 feet. From time 6 seconds to the 8.5 second mark, he drinks some water on the step 3 feet off the ground. Afterward drinking the water, he takes 1.5 seconds to descend to the ground and then he walks into the kitchen. The video ends at the 15 second mark. b) Make up an elevation-versus-time graphing story for the following graph: B A C E D 42 x 2 x 1 Example 4 Given f ( x) 2 x 3 x 1 and t 3 t g (t ) 2 t 3 t 1 3 a) find f (2) . c) evaluate g (3) . b) find f (1) . d) determine g (2) . x 1 x 0 You Try) Given f ( x) x 1 x 0 e) evaluate f (1) . f) find f (0) . Example 5 Write a function that models each graph. a) b) 43 c) d) 44 Homework for 1.3 Day 1 & 2 Pg 39 #41, 45 and Pg 83 #65 Evaluate all three problems for f(1). 41. 45. f(1) = f(1) = 65. f(1) = 45 Homework for 1.3 Day 1 & 2 Write a piecewise equation that represents each of these graphs. 1. 2. 3. 4. 5. 46 Date _______ Notes: 1.3 Day 3 & 4 Essential Questions: 1. How can patterns, relations, and functions be used as tools to best describe and help explain real-life situations? Learning Target: 1.3.4 I can identify whether or not a graph represents a function. 1.3.5 I can identify the domain and range of a piecewise graph using interval notation. 1.3.6 I can identify the increasing, decreasing, and constant intervals using interval notation. Vocabulary function function notation increasing interval domain range vertical line test horizontal line test decreasing interval constant interval relative maximum relative minimum Definition of a Function: Vertical Line Test: Example 1 Using the Vertical Line Test to determine if a graph represents a function: a) b) c) Graph y x 3 4 and determine if the equation represents y as a function of x. 47 Definition of the Domain of a Function: Tips: Look for values that you cannot have: Can’t have zero in the denominator Can’t have negative numbers under the radical Otherwise, usually, the domain is all real numbers, which is written ___________ in interval notation. Definition of the Range of a Function: Tips: Look for values that you cannot have: Can’t have radicals equaling negative numbers Can’t have absolute values equaling negative numbers Otherwise, usually, the range is all real numbers, which is written ___________ in interval notation. Example 2 Sketch the functions on the grid provided then determine the domain and range. Use the tips above verify your answer. a) g ( x) 2 x 3 3 b) f ( x) x 6 2 Domain:_______________ Domain:_______________ Range:_______________ Range:_______________ 48 c) f ( x) x 5 d) p( x) x 2 3 Domain:_______________ Domain:_______________ Range:_______________ Range:_______________ x 3 x 1 e) g ( x) x4 x3 4 1 f) h( x) x 1 4 x 2 +3 x 3 0 x3 x3 Domain:_______________ Domain:_______________ Range:_______________ Range:_______________ 49 In general, what does an increasing, decreasing, and constant interval look like? How does it relate to slope? Example 1 Determine the intervals on which the function is increasing, decreasing or constant. Use interval notation. a) Increasing _______________________ Decreasing _______________________ Constant _________________________ b) Increasing _______________________ Decreasing _______________________ Constant _________________________ c) Increasing _______________________ Decreasing _______________________ Constant _________________________ 50 d) Increasing _______________________ Decreasing _______________________ Constant _________________________ Example 4 Now try to put all of the elements together. Determine the domain, the range, and the intervals on which the function is increasing, decreasing or constant. Use interval notation. a) b) Domain _________________________ Domain _________________________ Range ___________________________ Range ___________________________ Increasing _______________________ Increasing _______________________ Decreasing _______________________ Decreasing _______________________ Constant _________________________ Constant _________________________ 51 Homework for 1.3 Day 3 & 4 Pg 38 11-16 Determine if the graph represents a function using the Vertical Line Test. Use the graph to determine the following information. 1. 2. Domain _________________________ Domain _________________________ Range ___________________________ Range ___________________________ Increasing _______________________ Increasing _______________________ Decreasing _______________________ Decreasing _______________________ Constant _________________________ Constant _________________________ 52 Pre-Calculus Chapter 1 Test Review - You may use a graphing calculator on this review. 1.1.2 I can find the slope given an equation of a line. 1.1.3 I can determine the y-intercept from a graph or an equation of a line. 1. Graph the function 3 x 4 y 12 . 1. 1.1.1 I can find the slope given two points. 1.1.5 I can write the equation of a line in point-slop form and slope-intercept form. 2. Find the equation of the line in slope-intercept form that passes through the points (-4, 2) and (-8, 5). 2. ______________________ 1.1.6 I can write the equation of a parallel line. 3. Find the equation of the line in slope-intercept form that 1 passes through the point (1, -9) and is parallel to y x 21 . 3 3. ______________________ 1.1.7 I can write the equation of a perpendicular line. 4. Find the equation of the line in point-slope form that passes through the point (-6, 2) and is perpendicular to 3x 9 y 12 . 4. _____________________ 1.1.8 I can write, and graph, the equation of vertical and horizontal lines. 5. Write the equation of a vertical line passing through the point (3, -2). 5. _____________________ 53 1.1.9 I can write the equation of a line that models a real world situation. 6. A salesperson receives a base salary of $75,000 and a commission of 8% of the total sales for the year. Write a linear model that shows the salesperson’s total income based on total sales of k dollars. 6. _____________________ Use the following table for questions 7-10. The table shows the sales S (in millions of dollars) for Timberland from 1995 to 2002. Use x = 0 for 1990. Year, x 1995 1996 1997 1998 1999 2000 2001 2002 Sales, S 665.1 690.0 796.5 862.2 917.2 1091.5 1183.6 1190.9 1.7.1 I can find the regression line equation given a set of points. 7. Use the regression feature on the graphing calculator 7. _____________________ to find a line of best fit (round to the nearest thousandths) for the data. Let x represent the year with x = 5 corresponding to 1995. 1.1.4 I can interpret what the slope, y-intercept, and x-intercept mean in a real life situation. 8. What does the slope represent in the context of the problem? Use the correct units and write the answer in a complete sentence. 1.7.2 I can analyze, interpret, and predict using the regression line. 9. Use the line of best fit or the table feature on your calculator to find the year in which the sales will exceed $1300 million. 9. _____________________ 1.7.2 I can analyze, interpret, and predict using the regression line. 10. Use the line of best fit to predict the average salary for the year 2006 (round to the nearest tenths place). 10. _____________________ 54 1.5.1 Given an equation written in function notation, I can evaluate the function algebraically. 3 1 11. Given the function (𝑥) = − 5 𝑥 + 4 , find 𝑓 (5). 11. _____________________ 1.5.2 I can evaluate a function using the graph. 12. Find g(4) using this graph. 12. _____________________ 1.3.2 Given a piecewise function, I can find the value of y algebraically. -2x+3 13. Given h( x) 1 x3 x 2 0 x3 13. _____________________ x3 find h(-1). 1.3.3 I can write a piecewise function from a graph. 14. 14. _____________________ 55 1.3.5 I can identify the domain and range from a piecewise graph using interval notation. 1.3.6 I can identify and describe increasing, decreasing, and constant intervals using interval notation. 15. Determine the domain, range, and the intervals on which the function is increasing, decreasing or Constant. Use interval notation. 16. Domain: ________________ Range: ____________________ Increasing: _________________ Decreasing: _________________ Constant: ___________________ 1.3.4 I can identify whether or not a graph represents a function. 16. Is y x 3 1 a function? 16. _____________________ Explain why or why not using complete sentences. 1.3.1 I can graph linear piecewise functions. 1 17. Graph the function: 𝑔(𝑥) = { 3 𝑥+5 |𝑥 − 3| + 1 𝑥<0 𝑥≥0 17. 56 Blank Page 57