Function Survey
Beware of Fake Tickets
Everyday sporting events and performances take place all over the world. Thousands of people buy tickets for these events and look forward to attending them. The video above about counterfeit tickets illustrates gaining admission to an event depends on having a legitimate ticket. Where you sit depends on the seat location listed on a legitimate ticket stub.
This concept of dependence is the basic idea of a function; especially if one quantity depends on another quantity.
Another common example of a function is ZIP codes. Each piece of mail with a ZIP code address is sent to exactly one post office location. The location where the the US postal service delivers the item depends on its ZIP code. For example:
There are also non-functions, where one quantity does not directly depend on the other. A person's name and email address are an example of a non-function. Do you or someone you know have more than one email address? Since there is more than one output of an email address for a person's name, then this is not a function.
Give an example of a function.
Give an example of a relation that is not a function.
Another common example of a function is ZIP codes. Each piece of mail with a ZIP code address is sent to exactly one post office location. The location where the the US postal service delivers the item depends on its ZIP code. For example:
- a letter marked 52654 is sent to Wayland, Iowa.
- a letter marked 99362 is sent to Walla Walla, Washington.
There are also non-functions, where one quantity does not directly depend on the other. A person's name and email address are an example of a non-function. Do you or someone you know have more than one email address? Since there is more than one output of an email address for a person's name, then this is not a function.
Give an example of a function.
Give an example of a relation that is not a function.