5.1 Identifying Functions

Front

What is a function?

Back

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

Front

Which set of ordered pairs is a function? {(9,5), (10,5), (9,-5), (10,-5)} or {(6,-5), (7,-3), (8,-1), (9,1)}?

Back

{(6,-5), (7,-3), (8,-1), (9,1)} is a function because each x-value is unique.

Front

What are the inputs in a function?

Back

Inputs are the x-values in a function.

Front

What is the range of a function?

Back

The range is the set of all output (y-values) of a function.

Front

What does it mean for a function to be one-to-one?

Back

A one-to-one function means that each input has a unique output, and no two inputs share the same output.

Front

Identify the function: A: {(1,2), (2,3), (3,4)}, B: {(1,2), (1,3), (3,4)}, C: {(2,2), (2,3), (3,3)}, D: {(4,5), (5,6), (6,7)}

Back

A and D are functions because each x-value is unique.

Front

What is the domain of a function?

Back

The domain is the set of all possible input (x-values) for a function.

Front

If a function has the ordered pairs {(1,2), (2,3), (3,4)}, what is the output when the input is 2?

Back

The output is 3.

Front

What is the vertical line test?

Back

The vertical line test is a method to determine if a curve is a function. If a vertical line crosses the curve more than once, it is not a function.

Front

What is an example of a non-function?

Back

The set {(1,2), (1,3)} is not a function because the input 1 has two different outputs.