Identifying a Function

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 two pairs have the same first element (x-value).

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, then the graph is not a function.

Front

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

Back

Yes, because each x-value is unique.

Front

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

Back

No, because the x-value '1' is associated with two different y-values.

Front

What does it mean for a graph to represent a function?

Back

A graph represents a function if every x-value corresponds to only one y-value.

Front

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

Back

{(1,2), (2,3), (3,4)} is a function.

Front

What is an example of a function?

Back

An example of a function is f(x) = 2x + 3.

Front

What is a non-function?

Back

A non-function is a relation where at least one input (x-value) has multiple outputs (y-values).

Front

How can you tell if a graph is not a function?

Back

If a vertical line crosses the graph at more than one point, it is not a function.