Bug in applet.getValueString("diff")?
The example at:
doesn't work here using GeoGebra pre-19th June.
The graphs are all drawn correctly but you get the wrong message if you get the answer correct.
is where the problem is I think.
It returns "ined" rather than the correct answer sometimes (when there are no xs in the answer?)
input -6x^2+5 output 2x - 3
input -6x^2+x+5 output x - 3
input -6x^2+2x+5 output ined
input -6x^2+3x+5 output -x - 3
(Windows XP, Java 6u1, Firefox 2.04/IE7)