Acc. Coordinate Algebra: Unit 3
Name___________________
Date_________________
Period________
Lesson 1: Identifying and Evaluating Functions
Guided Notes
Standard and Skills
F.IF.1 Understand that a function from one set (called the domain) to another set (called the range) assigns to each
element of the domain exactly one element of the range. If f is a function and x is an element of its domain, then f(x)
denotes the output of f corresponding to the input x. The graph of f is the graph of the equation y=f(x).
F.IF.2 Use function notation, evaluate functions for inputs in their domains, and interpret statements that use
function notation in terms of a context.
SWBAT identify whether a relation is a function by looking at a graph, table of values, or an equation.
SWBAT use function notation to evaluate the output of a function given a particular input.
SWBAT identify the domain and range for a set of values.
Part I: Identifying Functions
Important Vocabulary
Relation: Any set of ____________________ that has an ______________________.
Function: A _____________________ such that every single _______________ has exactly _________________ output.
Input (x-coordinates): also called the __________________.
Output (y-coordinates): also called the ________________.
How to Determine if a Relation is a Function:
1. If we are looking at a table of values, each input must have ______________________ output.
2. If we are looking at the graph….we must use the vertical line test: No vertical line can pass through
_______________________________________ points on the graph.
Example 1: Does the relationship represent a function?
Function: y  x  6
x (input)
-3
0
7
8
y (output)
-9
-6
1
2
Example 2: Does the relationship represent a function?
Example 3: Does the relationship represent a function?
y = 3x
x=3
y =3
Guided Practice
Are these relations functions? Give an explanation on the right hand side.
1.
 3,2  ,  4,3  ,  5,4  , 6,5 
2. 2.
3.
3.
4.
Table of Values
5.
input
3
2
0
3
output
4
-1
2
-3
Independent Practice
Explain whether the relation is a function or not.
1.
4.
2.
Input
1
2
Output
7
-7
8
-8
5.
3.
Input
Output
3
5
7
2
4
6
6.
Input
0
2
4
6
Output
-6
-4
-2
0
Part II: Using Function Notation
What is function notation?
Function Notation is _________________________________________________. It is pronounced
________________________.
f(x) is a fancy way of writing _____ in an _______________.
Example 1: Evaluate f  x   x2  2x  3 , when x  3 and x  4 .
Guided Practice
Evaluate the function when x  3, x  0, and x  2 .
1.
f  x   2x  5
2.
h  x   6x  2
3.
g  x   2.4x
Independent Practice
Evaluate the function x  3, x  0, and x  2 .
1.
f  x   0.5x  12
2.
h x  
2
x 1
3
3.
f  x 
3
x2
5
4. f(x) = x2 – 2x + 7
5. f(x) = 3x