A wonderful tool to introduce students to graphing especially if students do not have graphing calculators.
I found this to be a great product for students to explore graphing concepts. It is designed for anyone above the age of 13. However, they also have an iPad app that is just as powerful and it does not require an internet connection. This graphing calculator website and app will do about 90% or more of what a graphing calculator will do. It can not do matrices yet, but they are working on it. They also have a "how to" hand out on functions you can use for graphing. The web version also an huge gallery of user created graphs as well. You also have the ability to create an account and be able to save and share your content with your class.
How I Use It
I have used this application to explore graphing y=mx+b with algebra students to explore how slope and the y - intercept values will affect the graph. I have also used this graph to explore graphing quadratic equations with students in algebra as well. One could explore a a multitude of other graphing concepts and even animate graphs to add motion to the graphs. You can graph in polar coordinates as well as graph inequalities easily. It easily creates sliders to manipulate the standard variables of equations like the "m" and "b" in y=mx+b or the "a", "b" and "c" of y=ax^2+bx+c as well as many more equations. The only downside is that their terms of service does not allow anyone under the age of 13 to use their website. But they have released an iPad app that works just as well.