Identifying Functions and Function Notation

8.5g Identifying Functions

By Jesus Saldana

Open Ended

What do we remember of finding if tables, graphs and charts are functions?

FUNCTION

a specific kind of relationship where every input has exactly one output.

Multiple Choice

Function or not a function

• function

• not a function

Multiple Choice

Which set of ordered pairs is a function?

• {(9,5), (10,5), (9,-5), (10,-5)}

• {(3,4), (4,-3), (7,4), (3, 8)}

• {(6,-5), (7, -3), (8, -1), (9, 1)}

• {(2, -2), (5, 9), (5, -7), (1, 4)}

Multiple Choice

Function or not a function

• function

• not a function

Fill in the Blank

The graph of a function must passed the ____________ line test.

Multiple Choice

Function or not a function

• function

• not a function

Multiple Choice

Is this a function

• Function
• Not a Function

Multiple Choice

Which of the following is NOT a function?

Multiple Choice

Is this a function?

• Function
• Not a Function

Poll

How comfortable are you with understanding how to find a function within the various mediums we saw today (Graphing, Tables, Mapping, Ordered Pairs)?

• Very Much Ready

• Ready but nervous

• Somewhat But I Still need guidance

• Can we redo, Teacher?

Function Notation

Objective: Evaluate functions written in function notation.

Function Notation

a specific way to write a relation when it is a function. ​

General Function Notation: f(x)

Said out loud: "f of x"

​

Example:

y = 3x + 2 is a function.

So it can be written as f(x) = 3x + 2

Multiple Choice

If f(x) = 2x + 1, find f(1).

• f(1) = 1

• f(1) = 4

• f(1) = 0

• f(1) = 3

Multiple Choice

Evaluate f(-2) if f(x) = x + 3

• -1
• 1
• 5
• -5

Multiple Choice

If I know that f(2) = 4, what is another way I can write my answer?

• 2,4

• (2, 4)

• That is the only way to write it.

Multiple Choice

For the function f(x) = -3(x-1) find f(0).

• 0
• -3
• 3
• -1

Open Ended

If you are having difficulty with the lesson, what part of the lesson would you like for me to revise or adjust to better help you understand?