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Re: Solving a DE using Mathematica


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]] &


First[(de /. {#, D[#, z, z]} & /@ sol[[1]])] // FullSimplify

gives true.

So what is your problem ?


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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