Re: Solving a DE using Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg90450] Re: Solving a DE using Mathematica*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Thu, 10 Jul 2008 06:32:11 -0400 (EDT)*Organization*: Uni Leipzig*References*: <g51uce$6tj$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, first you should not use 0.016 and I change it to the symbol a de = (-l^2 - m^2 + n^2/(r + a*z)^2) Z[z] + Z''[z] == 0 sol = DSolve[de, Z[z], z] // FullSimplify[#, Element[{l, m, n}, Integers]] & and First[(de /. {#, D[#, z, z]} & /@ sol[[1]])] // FullSimplify gives true. So what is your problem ? Regards Jens Greg wrote: > I'm having problems solving this problem although it should appear pretty straightfoward: > > (-l^2 - m^2 + n^2/(r + 0.016 z)^2) Z[z] + Z''[z] == 0 > > I am solving for Z[z]. These are the lines I use: > > DSolve[Above Equation, Z[z], z] > > I get an odd solution so I do a solution check plugging back in Z[z] and Z''[z] yet I don't get 0. In the above, l,m,n,r are all constants. >