a problem about NDSolve and NIntegrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg79936] a problem about NDSolve and NIntegrate*From*: lynn <lynn0701 at gmail.com>*Date*: Thu, 9 Aug 2007 05:18:27 -0400 (EDT)

Hello, I'm tring to solve a diffrential equation with its upper boundary as a variable. and then I want to integrate it, and define it as a funcion with two variable. However, I don't know why it doesn't work at the second step. my equation is as following, f[c_?NumberQ]:=y[x]/.NDSolve[{eqn,y[0]==1,y'[0]==0},y,{x,0,c},MaxSteps- >10000][[1]] n[w_NumberQ,c_NumberQ]:=NIntegrate[c*y[x]*(r-w)],{r,w,1}] function f works well, however there's some problem in funcion n, and it's confused me for a long time..., thanks for your help!! Best Regards!! Lynn