Subject: bug in integrate, is anyone working on this?
From: Jaime Villate
Date: Sun, 03 Jun 2012 11:27:06 +0100
On 06/02/2012 07:07 PM, Stavros Macrakis wrote:
> So the current Maxima results are arguably correct (with the arbitrary
> choice of +x rather than -x over the whole range).
But that "correct" result makes Maxima inconsistent with itself:
float (subst (x=-1, sin(x)^2/sqrt(1-cos(x)^2))) ---> .841470984807896
float (subst (x=1, sin(x)^2/sqrt(1-cos(x)^2))); ---> .8414709848078966
plot2d (sin(x)^2/sqrt(1-cos(x)^2), [x,-1,1]) ---> integral not equal to
zero.
Jaime
>
>
>
> On Sat, Jun 2, 2012 at 1:25 PM, Richard Fateman
> <fateman at eecs.berkeley.edu <mailto:fateman at eecs.berkeley.edu>> wrote:
>
> sin(x)^2/sqrt(1-cos(x)^2);
>
> integrate(%,x,-1,1) returns 0, but the integrand is
> always non-negative.
>
> integrate(%,x) returns cos(x) which is not
> right either.
>