1. Functions
Rules and Tables

2. Vocabulary
Function-is a relationship in which each input has exactly one output.
A Function consists of:
Domain- (x coordinate) A set called the domain containing numbers called inputs.
Range- (y coordinate) A set called the range containing numbers called output.

3. Example 1 Identify the domain and range of the function.
Range: 1, 2, and 5
Input X 1 2 4 5 2 2 1
Output Y

4. Make a table for a function
The domain of the function y = 2x is 0, 2, 5, 7, and 8. Make a table for the function..
The range of the function is 0, 4,10,14, and 16.
Solution: 5 X 2 7 8
y = 2x
2(2)=4
2(7)=14
2(8)=16
2(0)=0
2(5)=10

5. Make a Table Make a table for the equation y = x – 5
The Domain (x coordinate, input)- {10, 12, 15, 18, 25}
Input X 18 25 10 12 15
Output X

6. Key Concept
Function Rule: A function may be represented using a rule that relates one variable to another.The output is 3 more than the input.
Equation: y = x + 3
Input, x 1 2 3 4
Output, y 5 6 7 3 4

7. Write a function rule Solution
Let x be the input or independent variable, and let y be the output, or dependent variable. Notice the each output is 2 more than the corresponding input. So, a rule for the function is y = x + 2 4 6
Input 1 10 8
Output 2 3 6 12

8. Write a Function Rule
If you are given the Function table write a function rule (equation).
Domain (input x){1,2,3,4}
Range (output){8,16,24,32}
Input x 1 2 3 4
Output y 8 16 24 32

9. Write a Function Rule Domain (input x){15,20,21,30,42}
Range (output y){7,12,13,22,34}
Input x 15 20 21 30 42
Output y 13 12 22 34 7

10. Practice
Questions