1. 2.3 Introduction to Functions
Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it.
Warm-up (IN)
Evaluate each expression. -7 3 16
-1.44 -8
0.001

2. Notes A set of #s pairing input and output values Relation – Domain -
Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it.
Notes
Relation –
A set of #s pairing input and output values
Domain -
The set of input values
Range -
The set of output values
Function -
A relation where there is exactly one output for every input
EX 1 – Identify the domain and range of the relation, then determine if it’s a function.
D: 1,2,3,4
R: -4,1,3
Yes, Function
D: -2,1,3,4
R: 1,2,3,4
No, Not a Function

3. EX 2 – Identify the domain and range of the graph.
Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it. c. x y
Yes, Function -2 -1 1 2 -5 -3
domain
range 1 1 3
EX 2 – Identify the domain and range of the graph. b. a.
D: -3,-2,1,3
R: -3,0,1,2

4. Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it.
Vertical Line Test – a relation is a function if and only if no vertical line intersects the graph at more than one point.
Ex 3 – Is the graph a function? a. b. c.
yes
yes no

5. can be written in the form
Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it.
Linear Function –
can be written in the form
Function Notation –
read: “f of x”, or “the value of f at x”
f(x) is the same as y!
Independent Variable –
the input, or x
Dependent Variable -
the output, or f(x)

6. Learning Objective: to state the domain and range of a relation and tell whether it is a function and to write a function in function notation and evaluate it.
Ex 4 –

7. Out – Describe 3 ways to represent a function.
Summary – I think I can remember…
HW – p #17-57 odd, 64,65, 67-69,75