1. 7.2 Functions
Lesson #7.2
Pg. 465

2. We have learned about Relations How to represent Relations Coordinates
We have learned about
Relations
Coordinates
(x, y)
How to represent Relations
Graph
(x, y) – Coordinates
Table
T – Chart
Mapping Diagram
X Y (each coordinate) X Y
Inputs
Outputs
Independent
Dependent
Domain
Range
Horizontal
Axis
Vertical
Axis

3. A function is a special type of relation that pairs each domain value with EXACTLY ONE range value.
Every function is a relation
But not all relations are functions.

4. Identifying Functions
Give the domain and range of the relation. Tell whether the relation is a function. Explain.
{(3, –2), (5, –1), (4, 0), (3, 1)}
D: {3, 5, 4, 3}
R: {–2, –1, 0, 1}
The relation is not a function. Each domain value does not have exactly one range value. The domain value 3 is paired with the range values –2 and 1.

5. Identifying Functions
Give the domain and range of the relation. Tell whether the relation is a function. Explain. –4 2 –8 1 4 5
D: {–4, –8, 4, 5}
R: {2, 2, 1, 1}
This relation is a function. Each domain value is paired with exactly one range value.

6. D: {–6, –4, 1, 8} R: {2, 1, 2, 9} D: {2, 2, 3, 4} R: {–5, –4, –3}
Try This!
Give the domain and range of each relation. Tell whether the relation is a function and explain.
a. {(8, 2), (–4, 1), (–6, 2),(1, 9)} b.
D: {–6, –4, 1, 8}
R: {2, 1, 2, 9}
D: {2, 2, 3, 4}
R: {–5, –4, –3}
The relation is a function. Each domain value is paired with exactly one range value.
The relation is not a function. The domain value 2 is paired with both –5 and –4.

7. Function Notation We will utilize equations Such as….
But in function notation it will look a little different
We will be solving for , the “y”, to get a coordinate for graphing.

8. Function Notation
You may be asked to substitute or fill out a “T” chart table
Substitution
T - Chart
You choose your inputs if not given to you in the question

9. Homework
Pg. 469
CC: 1-7, 12-13
HC: 1-13