excellent

This application deserves a very good mention. It is perfect way to visualize any function in 2D or 3D with strightforward writing, go "inside" the graph and play with it at your will. A powerful tool to play with maths and having fun while learning.
I use it every time I run into complicated formulas in physics to "sniff" at where the behavior consistently goes. That greatly helps to test the coherence beneath the maths.
I regret not to have had such a too, in my early days as a student, I d certainly saved a bunch of time...

nando2011 about Quick Graph, v2.4