maxima question: integration



On Wed, May 26, 2010 at 10:04, ALEXIOU SPURIDON <moka1 at otenet.gr> wrote:

> For version 0.8.4:
> first I do a diff:
> diff(sinh(x)/(e*cosh(x)-1),x,1);
> I get the right result
> cosh(x)/(e*cosh(x)-1) - esinh(x)**2/(e*cosh(x)-1)**2)
>
> what wxmaxima fails to realize is that if we homogenize and
> use cosh(x)**2-sinh(x)**2=1
> we get the simple result  (e-cosh(x))/(e*cosh(x)-1)**2
>

factor(trigsimp( ... )) will put it in that form.


> Perhaps because of that when I try
>
> integrate((e-cosh(x))/((e*cosh(x)-1)**2,x);
> it asks me whether 1-e**2 is positive or negative


I don't understand what this has to do with the simplification question. Can
you elaborate?

(and does not allow me to answer)
>

What do you mean "does not allow me to answer"?  Perhaps this is a wxmaxima
problem? (I'm afraid I don't use wxmaxima.)  It works fine in xmaxima.


> I wonder if there is a way to improve on such integrations....
>

Improve in what way?

            -s