1. 3.1 Relations and Functions

2. Vocab Relation: a set of ordered pairs
Domain: All possible x values (inputs)
Range: All possible y values (outputs)
Function: a relation that has only ONE range for every domain

3. Functions? 1) Domain Range 2) Jorge 202 Domain Range Carolyn 142
Elaine 138
Saul
This is a function. Each input has only one output. 2)
Domain Range
Cheese pizza $9.75
Tomato pizza $7.25
Meat pizza $8.50
This is not a function. The cheese pizza (input) has two outputs.

4. Functions?
3) (2, 4)(3, -12)(2, 9) (6, 3)
Not a function because the domain of 2 has two different ranges.
4) (-1, 6) (5, 7)(9, 6)
This is a function.

5. Functions? Try this… Domain Range A 4 B 0 C
Yes this is a function. Each input only has one output.

6. Functions Try this again…. Domain Range P 0 Q 1 R 1
No this is not a function.

7. What is the domain and range of each function?
Example 1:
h: {(4, 0)(6, 0) (2,0)}
Domain: {2, 4, 6}
Range: {0}
Example 2:
j: {(1, 5)(3, 7)(1, 7)}
Domain: {1, 3}
Range: { 5, 7}

8. Domain and Range? Try this… 1.) {(Tom, 18)(Sue, 12)(Sue, 28)}
Domain: { Tom, Sue} Range: {12, 18, 28}
2.) 3 36
7 35 6
Domain: {3, 6, 7} Range: {35, 36}

9. Function Notation
f(x) is function notation, where x is your input and f(x) is your output.
f(x) = x + 2, find f(8)
f(8) = 8 + 2
f(8) = 10

10. Try this.. Find f(-2), f(0) and f(3) for f(x) = 2x + 1 f(-2) = -3