Hello, here is for the background : http://en.wikipedia.org/wiki/Lane-Emden_equation and indeed checking for n=1 that sin(x)/x is a solution : In [16]: diff(sin(x)/x, x,2)+2/x*diff(sin(x)/x,x)+sin(x)/x works like a charm.
But: In [14]: dsolve(f(x).diff(x, x)+2/x*f(x).diff(x)+f(x),f(x)) Out[14]: C₁⋅sin(x sqrt(3)) + C₂⋅cos(x⋅sqrt(3) ) Obviously I am doing something wrong... Thanks for your help. I just downloaded sympy using git, so I have In [3]: sympy.__version__ Out[3]: '0.6.4.beta1' best, and kudos for the great package, Johann --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
