Functions, Tables, Range, Domain.. Whatever you want to call it.. ?

Question

At a yard sale you find 5 paperback books by your favorite author. Each book is priced at $.75

a. Describing in Words: For each book you buy, you spend $.75, so _____ is a function of _____.

b. Writing a Rule: Write a rule for the amount (in dollars) you spend as a function of the number of books you buy. Indentify the domain of the function.

c. Making a Table: Make a table and identify the range of the function.

Answer 1

a) The total you spend is a function of the number of books you buy.

b) n ↦ 3/4 n = c, where n is the number of books, and c the total cost.  The domain is the non-negative integers (you can only buy a whole number of books, or none).

c)

n c

----------

0 0

1 3/4

2 3/2

3 9/4

4 3

The range is the set {0, 3/4, 3/2, 9/4, 3, ....}.