Vocabulary
Evaluating Functions
Function or Foe
Tables & Graphs
Function Fun
100
What is the definition of input?
All the x values
100
Evaluate f(2) if f(x)=-3x
f(2) = -6
100
Is it #1 a function? How do you know?
No! The input 3 has two different outputs
100
Is it a function?
| x | y |
| 3 | 7 |
| 5 | 9 |
| 3 | 8 |
No! The input 3 has two different outputs (7 and 8)
100
Is it a function? Justify your answer.
{ (2, 3), (4, 5), ( -2, 6), (-4, 3) }
Yes, each input has exactly one output.
200
What is an output?
All values of y
200
Evaluate the function, y= -1(4x+2), when x=7
-30
200
Is it #3 a function? How do you know?
Yes! Every input has exactly one output.
200
Is it a function? Why or why not?
Yes! Every input has exactly one output AND it passes the vertical line test
200
Is #7 a linear or nonlinear function? How do you know?
Linear!
300
What is the definition of a function?
A relationship between input and output values. Each input has exactly one output value.
300
Evaluate f(-6) if f(x)=x^2 - 9
f(-6) = 27
300
Is #4 a function? How do you know?
Yes! Every input has exactly one output
300
Is it a function? Why or why not?
No! It does not pass the vertical line test.
300
Is #8 a function or a relation? How do you know?
It is a relation... not a function!
400
What is the definition of a relation?
A set of ordered pairs: inputs and outputs
400
Evaluate the function, y=25-4x if x=9
-11
400
Is #2 a function? How do you know?
No! The input 4 is matched with two different outputs
400
How would you explain what a function is to your friend that is completely confused? What do you look for when deciding if something is a function or not?
Answers will vary.
400
Is it a function? Justify your answer.
Yes, it passes the Vertical Line Test.
500
What is the test to tell if a graph is a function?
Vertical Line Test
500
If f(x)=3x^2+15 then find f(4)
63
500
Is #5 a linear function? How do you know?
No! The inputs are constant, but the outputs do not increase or decrease at a constant rate.
500
Is #6 a linear or nonlinear function? How do you know?
Nonlinear!
500
Is it a function? Justify your answer. 
Yes, each input has exactly one output.