Algebra and Trigonometry, 5th Edition

1.2 Functions and Graphs

• Determine whether a correspondence or a relation is a function.

• Find function values, or outputs, using a formula or a graph.

• Graph functions.

• Determine whether a graph is that of a function.

• Find the domain and the range of a function.

• Solve applied problems using functions.

We now focus our attention on a concept that is fundamental to many areas of mathematics—the idea of a function.

Functions

Used-Book Co-op. A community center operates a used-book co-op, and the proceeds are donated to summer youth programs. The total cost of a purchase is $2.50 per book plus a flat-rate surcharge of $3. If a customer selects 6 books, the total cost of the purchase is

$$\mathrm{\$2.50}(6)+\mathrm{\$3},\text{or}\mathrm{\$18.}$$

We can express this relationship with ...