Identifying Functions

Front

What is a function?

Back

A function is a relation where each input (x-value) has exactly one output (y-value).

Front

How can you identify a function from a set of ordered pairs?

Back

A set of ordered pairs is a function if no x-value is repeated with different y-values.

Front

What is the vertical line test?

Back

The vertical line test states that if a vertical line intersects a graph at more than one point, the graph is not a function.

Front

Is the set {(1, 2), (2, 3), (1, 4)} a function?

Back

No, because the x-value 1 is paired with two different y-values (2 and 4).

Front

Is the set {(5, 6), (7, 8), (5, 9)} a function?

Back

No, because the x-value 5 is paired with two different y-values (6 and 9).

Front

What does it mean for a relation to be not a function?

Back

A relation is not a function if at least one x-value is associated with more than one y-value.

Front

Which of the following is a function: {(2, 3), (3, 4), (2, 5)} or {(1, 2), (2, 3), (3, 4)}?

Back

{(1, 2), (2, 3), (3, 4)} is a function because all x-values are unique.

Front

What is an example of a function in real life?

Back

An example of a function is a vending machine: each button (input) gives one specific item (output).

Front

How can you tell if a graph represents a function?

Back

If any vertical line drawn on the graph intersects it at most once, then it represents a function.

Front

What is the definition of a relation?

Back

A relation is a set of ordered pairs, which can include functions but does not have to.