1. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 1 5-1 CLASSIFIED ADS Compute the cost of classified ads for used cars. Compute the cost of sales tax on automobiles. OBJECTIVES

2. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 2 sales tax - Sales tax is required to be paid when you purchase an automobile. Sales tax is figured on the purchase price of the vehicle. If the vehicle is new and has never been titled, the tax will be figured on the difference between the purchase price and any trade-in amount. If you buy a vehicle outside of Ohio for use in Ohio, credit may be given for any tax paid to the other state and may be deducted from taxes due in Ohio. domain - the set of values that can be input into a function. piecewise function - A function that gives a set of rules for each domain of the function (also called split functions.) cusp – the point of intersection of the two lines of a piecewise function Key Terms

3. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 3 Visuals Piecewise function

4. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 4 How do buyers and sellers use classified ads for automobiles? What are common car options that might be listed in a classified ad? What are their abbreviations?

5. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 5 Example 1 Kerry purchased a used car for $7,500 and had to pay 8½% sales tax. How much tax did she pay?

6. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 6 OYOOYO Mike wants to purchase a used car and he’s going to pay cash. The car is advertised for $8,250 and there is a pay 7% sales tax. If Mike has $8,500 in an account, does he have enough?

7. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 7 The sales tax rate in Mary Ann’s state is 4%. If she purchases a car for x dollars, express the total cost of the car with sales tax algebraically. CHECK YOUR UNDERSTANDING

8. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 8 Example 2 The cost of a classified ad is determined by its length. John plans to sell his car and places a 5-line ad. The newspaper charges $31 for the first two lines and $6 per extra line to run the ad for one week. What will John’s ad cost to run for two weeks?

9. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 9 EXAMPLE 3 Jason works for the Glen Oaks News and is writing a program to compute ad costs. He needs to enter an algebraic representation of the costs of an ad. His company charges $42.50 for up to five lines for a classified ad. Each additional line costs $7. Express the cost of an ad with x lines as a function of x algebraically.

10. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 10 The Smithtown News charges $38 for a classified ad that is 4 or fewer lines long. Each line above four lines costs an additional $6.25. Express the cost of an ad as a piecewise function. CHECK YOUR UNDERSTANDING

11. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 11 Roxanne set up the following piecewise function which represents the cost of an auto classified from her hometown newspaper. c(x) = 41.55 when x ≤ 6 41.55 + 5.50(x − 6) when x > 6 If x is the number of lines in the ad, use words to express the price c(x) of a classified ad from this paper. Example 4

12. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 12 CHECK YOUR UNDERSTANDING 60 when w ≤ 5 60 + 8( w − 5) when w > 5 p(w) = The following piecewise function gives the price p(w) of a classified ad in a classic car magazine. If w is the number of lines in the ad, use words to express the price p(w) of a classified ad from this paper.

13. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 13 EXAMPLE 5 Graph the piecewise function Roxanne created in Example 4.

14. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 14 CHECK YOUR UNDERSTANDING Find the cusp of the graph of the following piecewise function. 42.50 when x ≤ 5 42.50 + 7(x − 5) when x > 5 c(x) =

15. Financial Algebra © 2011 Cengage Learning. All Rights Reserved. Slide 15 5-1 CLASSIFIED ADS Compute the cost of classified ads for used cars. Compute the cost of sales tax on automobiles. OBJECTIVES