Comment #2 on issue 1779 by ness...@googlemail.com: When atan2 is used, expression can not be differentiated anymore.
http://code.google.com/p/sympy/issues/detail?id=1779
Pull request: https://github.com/sympy/sympy/pull/198 -- You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to sympy-issues@googlegroups.com. To unsubscribe from this group, send email to sympy-issues+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en.