Two questions---nonevaluated Integrate; NIntegrate inside NDSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg15082] Two questions---nonevaluated Integrate; NIntegrate inside NDSolve*From*: Benjamin Lotto <belotto at vassar.edu>*Date*: Thu, 10 Dec 1998 03:13:12 -0500*Organization*: Vassar College*Sender*: owner-wri-mathgroup at wolfram.com

[Contact the author to obtain the notebook mentioned - moderator] I have two questions about using Mathematica v3.0 to solve a problem I'm working on. 1) An intermediate step involves a definite multiple integral that I know can't be evaluated. When I type in into Mathematica, it tries to evaluate it and runs out of memory, at which point the kernel quits. I'd like to tell Mathematica not to try to evaluate the integral but to leave it unevaluated. How can I do this? See the attached notebook example1.nb. 2) More important, I'd like to be able to numerically solve a differential equation that involves a numerically evaluated integral. See the attached notebook example2.nb for an example of what I'd like to do. How do I manage this? It seems that I should be able to put any numerically evaluatable function of y and y' into NDSolve and it shouldn't complain. How can I do this? Thank you very much for the help. I'm running Mathematica on a Mac PowerPC 9500, system 8.5.