Chapter One Section One: Definition of a Function!

What is a Function?!

A function is a "relation between two sets in which one element of the second set is assigned to each element of the first set" (dictionary.com)

DIFFERENCE Between Relations and Functions:

A function is a special kind of relation. No two values of y can share one x value. A relation doesn't have this same requirement.

To Better Understand the DIFFERENCE Between Relations and Functions Visit:
http://www.purplemath.com/modules/fcns.htm

Is This a Function?

• You can test for this by utilizing the idea of the vertical line test
• Seeing how many domain values correspond to co-domain value and vice versa.
• (making sure a vertical line does not cross a graph more than once in one location)
• (for information on domain, range, and codomain, go to this video created by Khan Academy:
  http://www.khanacademy.org/math/algebra/algebra-functions/v/a-more-formal-understanding-of-functions)

Some Ways to Express Functions:

One way to demonstrate the meaning of a function!!!!!

• Mapping
• Graphing
• Diagrams
• Equations

Examples of Different Kinds of Functions:

• Linear
• Quadratic
• Polynomial
• Absolute Value
• Exponential
• Circular
• Logarithmic
• And Many More :)

Some more examples and these listed can be found at:
http://www.drdelmath.com/special_topics/Functions%20-%20Examples%20-%20Introduction.pdf

Olivia Kurajian- 1st Hour