DSolve bug: addendum to previous posting
- To: mathgroup at yoda.physics.unc.edu
- Subject: DSolve bug: addendum to previous posting
- From: <Constantin.Kahn at cdc2.c.mathematik.uni-hannover.dbp.de>
- Date: 17 Feb 92 10:40
Hi, one person claimed that my posting about a bug in DSolve which caused it to return wrong explicit solutions for the system of differential equations a'[t] - Cos[t] b[t] == 0 && b'[t] + Cos[t] a[t] == 0 was easily misunderstood. I did not intend to say that the auxiliary functions A[t] and B[t] were solutions. Of course they aren't. They are equal to the "solutions" returned by Mathematica. I introduced them to show that in this particular case Simplify doesn't perform up to its name. Besides, there are valid explicit solutions satisfying a[0] == 0 && b[0] == 1 given by a[t] = Sin[Sin[t]] and b[t] = Cos[Sin[t]]. Regards, Constantin Kahn