The Function Institute from Zona Land


This gives comprehensive discussion on definition of a function with Java Applets that illustrates very clearly one-to-one, one-to-many, many-to-one concepts.  It has pages on different types of functions (linear, polynomial, rational, exponential, trigonometric) and their interactive graphs.



Functions, Graphing, and Modeling


A large interactive tutorial using a Java program as a graphing tool, aimed to prepare students for calculus.  Topics include functions, graphing, exponential, logarithmic, trigonometric, and algebraic functions.



Maths Online Gallery: Functions 1


Collection of Java applets with exercises and some lesson plans: Function and graph, Recognize function graphs puzzles, Polynomial of third order, and a Function plotter.



Maths Online Gallery: Functions 2


Collection of Java applets with exercises:  Recognize function graphs puzzles that concentrate on negative power functions and trigonometric functions, and graph collections of exponential & logarithmic functions, and trigonometric functions.