Re: newbie question DSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg52161] Re: newbie question DSolve*From*: p-valko at tamu.edu (Peter Valko)*Date*: Sat, 13 Nov 2004 04:40:10 -0500 (EST)*References*: <cmppui$mll$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Let us use the values: d=1/2; L=1; yL=1; and denote the unknown y[d] by yd. Then Solve[ yd == (y[x]/. DSolve[{-y[x] + Derivative[2][y][x] ==DiracDelta[d-x]*yd, y[0] == 0, y[L]== yL}, y[x], x][[1]])/.x->d]; %//InputForm {{yd -> (2*Sqrt[E])/(1 + 3*E)}} Regards Peter "Pratik Desai" <pdesai1 at umbc.edu> wrote in message news:<cmppui$mll$1 at smc.vnet.net>... > Hello all > > I am trying to use DSolve to solve a ode with discontinuity in it (wave > equation with a viscous damper injected at a location d) > > This is what i am using > > DSolve[{y''[x]-lamda^2*y[x]==DiracDelta[x-d]*y[x],y[0]==0,y[L]== > =0},y[x],x] > > the problem I am facing is that > > y[x] on the right hand side (next the delta function) varies w.r.t to > the location > > y[x]==y[x]&& 0<=x<=d > y[x]==y[L-x]&&d<=x<=L > > I can solve the above equation without the y[x] coupled to the delta > function > > Please advise and thanks in advance, > > > Pratik Desai > > > ps: This is my third attempt at posting my query, I hope this time it > makes it to the list :)

**Follow-Ups**:**Re: Re: newbie question DSolve***From:*"Pratik Desai" <pdesai1@umbc.edu>