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Topic: Integrate with unknow function
Replies: 2   Last Post: Mar 24, 2013 4:16 AM

 Messages: [ Previous | Next ]
 Murray Eisenberg Posts: 2,105 Registered: 12/6/04
Re: Integrate with unknow function
Posted: Mar 24, 2013 4:16 AM

Either I'm not understanding something here or you didn't explain the situation precisely. . .

Is f just a symbol, or is there already an actual definition in the form
f[d_] := (some expression in d) ?

In any case, when you integrate with respect to d, that's a "dummy variable", so you would never expect to get an answer with a d in it.

At the very best, you might hope that the difference reduces to Integrate[f[d], {d, 2, 3}], for a specific function f.

Incidentally, d is probably a very bad name for the variable of integration!

On Mar 23, 2013, at 3:25 AM, Shan <shan.pub@gmail.com> wrote:

> Hi,
>
> I have a very rookie question as follows:
>
> Integrate[f[d], {d, 0,3}] - Integrate[f[d], {d, 0,2}]
>
> How can I get the result as f[d]? Thanks very much for any help!
>
> shan

---
Murray Eisenberg murray@math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2838 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305

Date Subject Author
3/24/13 Murray Eisenberg
3/24/13 Bob Hanlon