Symbolic for TI-83

http://www.detachedsolutions.com/symbolic/

Here is a link to the program for symbolic differentiation as well as other things for your TI-83 calcs. I haven't used it, so make sure you use the site to learn how it works too!

http://www.detachedsolutions.com/symbolic/software.php

You might want to add Pretty Print as well to help make the answers readable. It may actually already come with Symbolic, but I'm not sure.