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Laplace Transform bug?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg36276] Laplace Transform bug?
  • From: Raul Martinez <rmartinez at vrinc.com>
  • Date: Thu, 29 Aug 2002 01:38:03 -0400 (EDT)
  • Organization: Vista Research Inc
  • Sender: owner-wri-mathgroup at wolfram.com

To the Group,



In[104]:=
LaplaceTransform[D[f[t],t],t,s]

Out[104]=
-f[0] + s LaplaceTransform[f[t],t,s]

In[105]:=
LaplaceTransform[Integrate[f[t],t],t,s]

Out[105]=
LaplaceTransform[Integrate[f[t] ,t], t, s]

Item 104 is correct, but item 105 is not. The correct 105 should be:

-f[0]/s + LaplaceTransform[f[t],t,s]/s .

If Mathematica can get 104 right, then it should also produce a correct
105.  This looks like a bug. Any thoughts on this?


(Note: Number 105 does not look like that on the notebook page. It shows
the indefinite integral with an integral symbol followed by f[t] dt
instead of the function Integrate[ ]. I've spelled it out because the
e-mail won't show the symbol.)

Thanks,

Raul Martinez
Vista Research, Inc.



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