Here is a cool graphing calculator I found as a Chrome plug-in, but which seems to work fine in Firefox, too. The Desmos graphing calculator is an easy-to-use graphing calculator that is fun to use. Click the “examples” tab on the right to get started.
https://www.desmos.com/calculator/#
Notice that the variables are assigned by adding an equation. For example, on the slope-intercept example m is defined as 2/3, and b=2. Then y=mx+b graphs a line with a slope of 2/3 and an intercept of 2.
You can also share your graphs online with one click: http://bit.ly/vb821j
