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Re: Integration problem

  • To: mathgroup at smc.vnet.net
  • Subject: [mg40607] Re: [mg40577] Integration problem
  • From: Dr Bob <majort at cox-internet.com>
  • Date: Fri, 11 Apr 2003 02:00:45 -0400 (EDT)
  • References: <200304100741.DAA24290@smc.vnet.net>
  • Reply-to: majort at cox-internet.com
  • Sender: owner-wri-mathgroup at wolfram.com

Evaluate

?C

and you'll see that C is used for the arbitrary constants in integration.  
But you've used C as a variable in your expression.  I recommend never 
making up variables that start with capital letters.

However, that's not really the problem, and I'm not sure what IS.  I do 
know the indefinite integral is undefined at the lower limit, however.

indef = Integrate[(a/Sqrt[a^2 - b^2])*
     ((a + d)/Sqrt[(a + d)^2 - b^2]), a, Assumptions -> {c > 0, d > 0}]; 
indef2 = FullSimplify[indef]
indef2 /. a -> b
Limit[indef2, a -> b]

Even the limit doesn't evaluate.  So -- I'm guessing Mathematica really tried, but 
couldn't integrate the sucker.

Bobby

On Thu, 10 Apr 2003 03:41:35 -0400 (EDT), stefano fricano 
<stefanofricano at yahoo.it> wrote:

> Dear friends,
>
> I encountered singular problem with Integrate[]
> function.
>
> If I write this command:
>
> \!\(Integrate[\(A\/\@\(A\^2 - B\^2\)\) \(A +
> d\)\/\@\(\((A + d)\)\^2 - \
> B\^2\), {A, B, B + C}]\)
>
> i.e. Integrate[( A /(A^2-B^2)^0.5 )*((A+d) / (
> (A+d)^2-B^2)^0.5 )) between B and B + C
>
> Mathematica Kernel block and close itself!
>
> Any idea?
>
> Stefano
>
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-- 
majort at cox-internet.com
Bobby R. Treat



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