Identifying Functions Mapping Diagrams

Does the following mapping diagram represent a function? Explain why or why not.

• Yes, each input has at least one output

• No, 40 has two different outputs.

• Yes, each output has at least one input

• No, 2 and 5 each have two different inputs.

A function is a relation such that...

• each input produces exactly one output

• each input produces more than one output

• each output is produced by exactly one input

• each output is produced by more than one input

Which of the mapping diagrams below represent functions? Check all that apply.

• 
• 
• 
• 

Does this scatter plot represent a function? Explain why or why not.

• Function: Each input has at least one output.

• Not a function: 2 has two different outputs.

• Function: Each output has at least one input.

• Not a function: -1 and 1 both have two different inputs.

Does the following graph represent a function?

• Yes, because each input has exactly one output.

• Yes, because each output comes from exactly one input.

• No, because there are multiple inputs.

• No, because there are multiple outputs.

Consider this graph of a function. An input of –2 would produce an output of...

• 0

• 1

• 2

• –2

Consider this graph of a function. Which of the following inputs would produce an output of 0? Check all that apply.

• 0

• 1

• 2

• –2

• –1

Does this graph represent a function? Explain why or why not. [Hint: look carefully at the dots.]

• Yes, each input has exactly one output.

• No, there are infinite inputs with an output of 2.

• No, 3 has two different outputs.

• No, the graph does not have a consistent slope.

Consider the graph. Which of the following are true statements about the equation represented by the graph? Check all that apply.

• It is a function

• It is not a function

• An input of 1 has an output of 1

• An input of 1 has an output of 3

• An input of 2 has an output of 2

In order to determine whether or not an equation is a function, you must first define the independent and dependent variable(s).

• True

• False