Bug in Mathematica 4.1?
- To: mathgroup at smc.vnet.net
- Subject: [mg29231] Bug in Mathematica 4.1?
- From: Daniel Arteaga <darteaga at ffn.ub.es>
- Date: Wed, 6 Jun 2001 04:24:19 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, Mathematica solves the differential equation x y''[x] + (x+1) y'[x] + (1 + r) y[x] == 0 giving two solutions of the equation, one in terms of Laguerre polinomials, and the other in terms of an hypergeometric function. But if you previously specify previously the value of r, let's say r=1, and also the corresponding bundary or ninitial conditions, then Mathematica 4.1 starts running forever, and does not give any solution. This behaviour is not present on Mathematica 4.0. I suspect that this is due to the fact that both solutions provided by Mathematica are not independent when r>0. The hypergeometric solution is a constant multiplied by the other solution. Mathematica 4.0 provided different solutions of the diff. eq., so that there was no problem. Regards, Daniel Arteaga