sqrt(1-x^2)/(2-2*x^2) --/--> 1/(2*sqrt(1-x^2))



Hmm... I'd forgotten about radexpand.

     expr: sqrt(1-x^2)/(2-2*x^2) $
     scanmap(factor,expr),radexpand:all;

gets you

     -%i/(2*sqrt(x-1)*sqrt(x+1))

The %i might be a bit inconvenient, but is nonetheless correct....  I
wonder if we have any code that will "notice" that the result is real iff
-1<x<1 and therefore rewrite it as say

    -1/(2*sqrt(1-x)*sqrt(x+1))

which is syntactically real.

           -s



On Wed, Feb 1, 2012 at 05:40, Barton Willis <willisb at unk.edu> wrote:

> Maxima calls inte to do integrate((sqrt(1-x^2)*(x^2+1))/(2-2*x^2),x,0,1).
> If I recall,
> inte is one of the last functions integrate tries. Some other method (not
> sure which one)
> handles integrate((x^2+1)/(2*sqrt(1-x^2)),x,0,1).
>
> integrate((sqrt(1-x^2)*(x^2+1))/(2-2*x^2),x,0,1) is in the testsuite.
>
> --Barton
>
>
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