Wolfram Research
Wolfram Math World: Function
Site offers a definition of a function. This definition may be difficult to grasp if you are not familiar with the mathematical language, however if you carefully read the definition, examples, and go to related links for unfamiliar...
University of Vienna (Austria)
Math Online: Functions
This interactive site uses applets to show sample graphs of each simple power function, a function plotter, graph puzzles, and more. Great site.
William Mueller
William Mueller: Families of Functions
Meet the Function Family! Each member of the family has examples of their graphs and descriptions of the types of real-world situation that produce those graphs.
Other
The Coordinate Plane: Graphs & Graphing Calculators
Site provides exercises for graphing on the coordinate plane including distance formula, midpoint formula, graphs of equations, and graphing using a calculator.
Wolfram Research
Wolfram Mathworld: Inverse Function
Site gives a definition of the inverse function as well as the example of the inverse of f(x)=x. Also included are formulas and links to related sites.
Hofstra University
Hofstra University: Applied Calculus: Function Grapher
Students enter functions in standard mathematic notation and the tool creates a graph of the function. Multiple functions can be entered into the learning tool.
Interactive Mathematics
Interactive Mathematics: The Graph of a Function
Several examples are presented to demonstrate the process of graphing functions, including linear, quadratic, and rational functions.
Interactive Mathematics
Interactive Mathematics: Functions and Graphs
The system created by Rene Descartes (1596-1650 CE) is explored in depth, covering topics such as definitions, notation, evaluating, domain and range, graphing and more. Interactive examples and demonstrations are enhanced using Live...