"Free tutorials using java applets to explore, interactively, important topics in precalculus such as quadratic, rational, exponential, logarithmic, trigonometric, polynomial, absolute value functions and their graphs. Equations of lines, circles, ellipses, hyperbolas and parabolas are also explored interactively. Graph shifting, scaling and reflection are also included. The definition and properties of inverse functions are thoroughly investigated. A graphical approach to 2 by 2 systems of equations is included. "
"GeoGebra
Free mathematics software for learning and teaching
must be Downloaded
* Interactive graphics, algebra and spreadsheet
* From elementary school to university level
* Free learning materials"
"MathBits.com is devoted to offering fun, yet challenging, lessons and activities in secondary (and college level) mathematics and computer programming for students and teachers."