Introduction to Functions

A plumber charges a service fee of $40 plus $25 per hour for labor.
Write a function rule for the total cost of hiring the plumber for a job that takes x hours.
How much would it cost to hire the plumber for a job that takes 4 hours?

• y = 40 + 25x
  $140

• y = 40x + 25
  $185

• y = 40 + 25x 
  $185

• y = 40x + 25 
  $140

A water tank holds 84 gallons. When it began to leak it lost 3 gallons every hour. Write an equation to find the amount of water "y" the tank will have after "x" number of hours.

• y = 84 - 3x

• y = 3 - 84x

All of the x values or inputs are called what?

• Domain

• Range

• Relation

• Function

All of the y values or outputs are called what?

• Domain

• Range

• Relation

• Function

State the range of the relation.

{ (3, -2) , (4, -3), (5, -4), (6, 0) }

• (3, -2, 4, -3)

• (-2, -3, 5, 0)

• { -2, -3, -4, 0 }

• { 3, 4, 5, 6 }

What is the range of the table?

• {-4, 0, 1, 3}

• {-2, 0, 2, 3}

• {-4, -2, 0, 1, 2, 3}

• { (0, 0), (2, -4), (3, 3), (-2, 1) }

List the ordered pairs

• (1,3), (2,6), (3,9), (4,12)

• (3,1), (6,2), (9,3), (12,4)

• Input and Output

• Output and Input

Is this table a function or not a function? 

• Function

• Not a Function 

Does the graph represent a function?

• Yes, because the vertical line test shows there are no repeating input values

• No, because the vertical line test shows there are repeating input values

Does this table represent a function?

• Function

• Not a Function