Re: Question for Partial differential summationseries

*To*: mathgroup at smc.vnet.net*Subject*: [mg122841] Re: Question for Partial differential summationseries*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Sat, 12 Nov 2011 07:33:30 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201111110952.EAA08411@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

> the exact solution is "p" (or P[i, xv]). With i undefined, that makes no sense. Bobby On Fri, 11 Nov 2011 03:52:55 -0600, dai <dahfsys at gmail.com> wrote: > The function defined as follow > > > x = X[t]; > y = Y[i, t]; > p = P[i, xv]; > w = Sum[y*p, {i, 1, N}]; > > When we excuted partial differential "w" by "y" > the exact solution is "p" (or P[i, xv]). > > However, the solution in Mathematica package is > Sum[p, {i, 1, N}]. > > How can I obtain the correct solution? please help. > -- DrMajorBob at yahoo.com

**References**:**Question for Partial differential summationseries***From:*dai <dahfsys@gmail.com>