Vocabulary
Evaluating Function Rules
Independent & Dependent
Domain & Range
Is it a Function?
100

What is the word for a set of input values (all values of x)?

Domain
100
Evaluate f(2) if f(x)=-3x
f(2) = -6
100

You and a friend are studying for a quiz. You want to get a higher score than your friend, so you decide to spend exactly 20 more minutes studying than your friend does. The relationship between these two variables can be expressed by the equation y=f+20, where f is the number of minutes your friend spends studying, and y is the number of minutes you spend studying. Identify the independent and dependent variables.

Independent Variable: The number of minutes your friend spends studying. Dependent Variable: The number of minutes you spend studying.

100

State the domain and range:

  x    y  
37
59
38

D: {3, 5}

R: {7, 8, 9}

100

Is it a function? Justify your answer. {(2, 3), (4, 5), ( -2, 6)}

Yes, each input has exactly one output.

200

What is the word for the set of output values (all values of y)?

Range

200

Evaluate f(7) if f(x)= 4x+2

f(7) = 30

200

Identify the independent variable: The relationship between the number of hours worked and the amount of money earned.

The number of hours worked.

200

State the domain and range:

D: {1, 2, 3, 4, 5, 6} R: {-1, 0, 1, 2, 3, 6}

200

Using the vertical line test, does the graph of the points (1,3) and (1,5) represent a function?

No, the points fail the Vertical Line Test.

300

What is the word for a relationship where each input has exactly one output value (the x's can't repeat)?

Function

300
Evaluate f(-6) if f(x)=x^2 - 9
f(-6) = 27
300

Identify the dependent variable: The relationship between your allowance and the number of chores you do.

Your allowance.

300

State the domain and range:

D: -4 ≤ x

R: all real numbers

300

Is it a function? Justify your answer.

  x    y  
24
15
26

No, the input of 2 has two different outputs.

400

Which variable affects the values of another variable? It is usually found on the x-axis of a graph.

Independent Variable

400
Evaluate f(x)=9 if f(x)=25 - 4x
x = 4
400

Identify the independent and dependent variables: You are buying boxes of cookies at a bakery. Each box of cookies costs $4.

Independent Variable: The number boxes of cookies purchased.

Dependent Variable: How much you spend at the bakery.

400

State the range:

R: y ≤ 3

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

Evaluate f(2) if f(x)=3x^2+15

f(2) = 27

500

Identify the independent and dependent variables: On your math quiz, you earn 5 points for each question that you answer correctly.

Independent Variable: Number of questions answered correctly.

Dependent Variable: Score on the quiz.

500

State the domain and range:

(5,2), (8,3), (-4,3), (1.5, 1.5)

D: {-4, 1.5, 5, 8}

R: {1.5, 2, 3}

500

Is it a function? Justify your answer. 

(-8, 0), (4,5), (2, 3), (-13, 0)

Yes, each input has exactly one output.