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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.
> 


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