4.6 - Formalizing Relations and Functions

4.6 - Formalizing Relations and Functions

Objective

• To determine whether a relation is a function

• To find domain and range and use function notation

Vocabulary

A relation is a pairing of numbers in one set, called the domain, with numbers in another set, called the range. A relation is often represented as a set of ordered pairs (x, y). In that case the domain is the set of x-values and the range is the set of y-values.

Essential Understanding

A function is a special type of relation in which each value in the domain is paired with exactly one value in the range.

Example

Open Ended

Identify the domain and range of the relation {(6,5),(4,3),(6,4),(5,8)}

Example

Multiple Choice

Is the relation a function? Use the vertical line test.

• Yes it is a function because it passes the vertical line test.

• Yes it is a function because it fails the vertical line test.

• No it is not a function because it passes the vertical line test.

• No it is not a function because it fails the vertical line test.

Example

​The function w(x)=250x represents the number of words w(x)you can read in x minutes. How many words can you read in 8 min?

Finding the range of a function

Independent Practice

Complete the 4.6 notes and practice problems.