The fx9860g serie of Casio calculators was designed to be used especially in high schools and contrary to Classpads it has no CAS.
During the last few years some developers have tried to create a CAS add-in for fx9860g calculators.
The first was kucalc (if I'm right) from UCF with symbolix in 2007. Symbolix has a good user interface and can do some algebra but as it is a beta version, contains some bugs.
After was created other cas add-in known as "jeuxcasio cas" by Alexis and Pierrotll. It is more reliable and stable than Symbolix. The last update was in 2008.
But now there is another alternative. Some days ago, Diameter released in CnCalc.org a port of Eigenmath Cas engine to fx9860g. It can derive and make much more such as simplify, roots...
Contrary to jeuxcasio CAS add-in, in Eigenmath fx 1.0 symbols like π (pi), √ (sqrt), cos, tan, sin and others are not (yet) associated with the calc keys and there is no function catalogue. Anyway I have to congratulate the author, he did an impressive work (again).
Source: http://www.cncalc.org/thread-9174-1-1.html