Chapter 1: Variables, Function Patterns, and Graphs 1.4 Patterns and Functions

Vocabulary Function – A relationship that assigns exactly one output value for each input value – For each input, there is only ONE corresponding output Function Rule – An equation that describes a functional relationship

“Function Machine”

Example 1 Suppose you are washing and drying clothes at a self-service laundry. The relationship between the number of loads (input) and the cost (output) is a function. Use the table to write a function rule. Number of Loads1234 Cost$2.75$5.50$8.25$11.00

Example 1a Write a function rule for the relationship between the number of hours (input) and the number of miles (output). HoursTotal Miles

Example 2 The relationship between the number of houses and the number of toothpicks is a function. Use the table to write a function rule. Number of Houses Total Number of Toothpicks

Vocabulary Dependent variable – Depends on the value of the independent variable Independent variable – Will occur regardless of what’s going on around it

Example 3 The table and graph model a function relating the storage capacity of a memory stick and its cost. Identify the independent and dependent quantities. Memory (MB) Cost ($)

Example 3a The cooking time for an unstuffed turkey is about 20 minutes per pound. What are the independent quantity and the dependent quantity for this situation?

Example 4 Maria earns $7 per hour for baby-sitting after school and on Saturday. She works no more than 16 hours per week. Identify the independent and dependent quantities for this situation.

Example 4 Maria earns $7 per hour for baby-sitting after school and on Saturday. She works no more than 16 hours per week. Find reasonable domain and range values for this situation.

Example 4a Charlie downloads songs for $.75 each. He has between $3.00 and $6.00 to spend on songs. Identify the independent and dependent quantities for this situation and find reasonable domain and range values.

Homework P even