Re: simple PDE?

*To*: mathgroup at smc.vnet.net*Subject*: [mg124959] Re: simple PDE?*From*: janos <janostothmeister at gmail.com>*Date*: Tue, 14 Feb 2012 06:39:21 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jh833o$omc$1@smc.vnet.net>

On Feb 12, 11:08 am, "Manuel G. Cerpa" <cerc... at gmail.com> wrote: > Hi members: > I need your help with this problem: > D[z[x,y],x] + D[z[x,y],y] + b*z[x,y] = 0, z[0,y]=1-Exp[-1000*y], z[x, > 0]=0, 0<x<1, y>0, b>0. > Using NDSolve with MethodOfLines, I have a error: mxst. > How solve it? > Best regards. Why don't you solve the equation symbolically to get z[x, y] -> E^(-b x) C[1][-x + y] then you will see immediately that the boundary conditons are contradictory. I hope this helps. J=E1nos