On 11/19/08, Mike Hansen <[EMAIL PROTECTED]> wrote:
> Yep, these are coming from Maxima:
>
> (%i11) integrate(x*abs(9-x^2), x, -6, 0);
> (%o11) 162
> (%i12) integrate(x*abs(9-x^2), x, -6, -3);
> (%o12) -729/4
> (%i13) integrate(x*abs(9-x^2), x, -3, 0);
> (%o13) -81/4
>
> I've CC'd Robert
I know Stavros M saw it and Mike cc'd Robert D, so two of the
main maxima developers definitely know about it now.
Thanks again.
On Thu, Nov 20, 2008 at 11:00 AM, pong <[EMAIL PROTECTED]> wrote:
>
> Yes, integral does not handle abs correctly.
>
> sage: integral(abs(x),x)
> integrate(abs(x), x)
Yes, integral does not handle abs correctly.
sage: integral(abs(x),x)
integrate(abs(x), x)
sage: integral(max(x,-x),x)
x^2/2
If that's for sure a bug coming from maxima, I hope someone it can be
reported to their bug list.
I can see that it has been reported by David to the maxima-user list,
bu
Thanks for reporting this. I emailed the maxima users list.
On Wed, Nov 19, 2008 at 11:50 AM, pong <[EMAIL PROTECTED]> wrote:
>
> Maybe someone has reported this already... but looks like there is a
> bug in integral
>
> sage: integral(x*abs(9-x^2), x, -6, 0)
> 162
>
> The integrand is negative
On Wed, Nov 19, 2008 at 8:50 AM, pong <[EMAIL PROTECTED]> wrote:
>
> Maybe someone has reported this already... but looks like there is a
> bug in integral
>
> sage: integral(x*abs(9-x^2), x, -6, 0)
> 162
>
> The integrand is negative on (-6,0)
Yep, these are coming from Maxima:
(%i11) integrate
As far as I can tell, this is a bug in maxima. Hopefully someone who
knows maxima better than I do can confirm that.
sage: maxima('integrate(x*abs(x^2-9),x,-6,0)')
162
-M.Hampton
On Nov 19, 11:19 am, Marshall Hampton <[EMAIL PROTECTED]> wrote:
> That looks like a bug. I will check if it is in
That looks like a bug. I will check if it is in trac already. Its
interesting that
integral(x*abs(9-x^2), x, -3, 0) + integral(x*abs(9-x^2), x, -6, -3)
returns the correct answer.
-M.Hampton
On Nov 19, 10:50 am, pong <[EMAIL PROTECTED]> wrote:
> Maybe someone has reported this already... but l
