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Vocabulary
Evaluating Function Rules
Independent & Dependent
Is it a Function?
100
What is the definition of domain?
A set of input values (all values of x).
100

Evaluate x=2 if y=-3x

y= -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=x+20, where x is the number of minutes your friend spends studying, and y is the number of minutes you spend studying. Identify the independent (x) and dependent (y) variables.

Independent (x) Variable: The number of minutes your friend spends studying. Dependent (y) Variable: The number of minutes you spend studying.

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 definition of range?
The set of output values (all values of y).
200

Evaluate x=7 if y= -(4x+2)

y= -30

200

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

The number of hours worked.

200

Do the points (1,3) and (1,5) represent a function?

No, the points share an input with 2 different outputs.

300
What is the definition of a function?
A relationship between input and output values. Each input has exactly one output value.
300

Evaluate x=-6 if y=x^2 - 9

y= 27

300

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

Your allowance.

300

Is it a function? Justify your answer.

xy
24
15
26

No, the input of 2 has two different outputs.

400

Which variable is the input, and which one is the output? 

(Which one is the x-variable, which one is the y-variable?)

x-variable is the input, y-variable is the output

(x - independent, y - dependent)

400

Evaluate y=9 if y=25 - 4x

x = 4

400

Identify the independent (x) and dependent variables (y): 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

what number could be used to make the following not a function?

                 x   y

                 1   3

                      5

                 4   9

1 and/or 4

500
What is the test to tell if a graph is a function?
Vertical Line Test
500

Evaluate y=42 if y=3x+15

x = 9

500

Identify the independent (x) and dependent (y) 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

Does the following list make a function? Why?

{(1,2), (-4,3), (6,3), (5,7)}

Yes, each input has exactly one output.