Evaluating Functions
Domain & Range
Is it a Function?
Evaluating Functions
100
What is the definition of domain?
A set of input values (all values of x).
100
What is the test to tell if a graph is a function?
Vertical Line Test
100
If f(x) = 9, use the equation f(x)= 3x and solve for x
3
200
Evaluate f(2) if f(x)=-3x
f(2) = -6
200
What is the definition of range?
The set of output values (all values of y).
200
Is it a function? Justify your answer.
| x | y |
| 2 | 4 |
| 1 | 5 |
| 2 | 6 |
No, the input of 2 has two different outputs.
300
Evaluate f(7) if f(x)= 4x+2
f(7) = 30
300
State the domain and range:
| x | y |
| 3 | 7 |
| 5 | 9 |
| 3 | 8 |
D: {3, 5}
R: {7, 8, 9}
300
Is it a function? Justify your answer.
{(2, 3), (4, 5), ( -2, 6)}
Yes, each input has exactly one output.
400
Evaluate f(x)=9 if f(x)=25 - 4x
x = 4
400
State the domain and range: 
D: {1, 2, 3, 4, 5, 6} R: {-1, 0, 1, 2, 3, 6}
400
Is it a function? Justify your answer.
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Yes, it passes the Vertical Line Test.