General Functions

General Functions

Key Terms

Function: A relation in which every input has one output.

Domain: The set of inputs in a function.

Range: The set of outputs in a function.

Representations of Functions and Non-Functions

Functions

Every input (# of days) has only
one output (amount of money).

Each input for the domain has
only one output.
Ex: (-3,3), (-2,6), (0,15)

Non-Functions

When the value 5 is an input, there
are three outputs, (4, 5, 7). In addition, some input values,
3 and 4, do not have any corresponding output
values.  Therefore, this is not a function.    

The Vertical Line Test

• Used to determine if a relation is a function.
• The graph is a function if no vertical lines can be drawn that intersect the graph at more than one point.