An integration bug



On 11/19/07, Milan Lukic <milan at eskimo.com> wrote:

> 'integrate(sqrt(9*x^2+37),x,0,2);

> changevar(%,3*x=sqrt(37)*sinh(t),t,x);

> 37*('integrate(cosh(t)*sqrt(sinh(t)^2+1),t,0,asinh(6/sqrt(37))))/3
> %,nouns;
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced .8717198386293096 by 8936/10251 = .8717198322114915
>
> `rat' replaced 1.128616979745806 by 9205/8156 = 1.128616969102501
> (%o402) 340585/24468

Almost the same behavior observed in Maxima 5.9.0 (GCL on Linux);
same messages from "rat" are printed, and then 13.91960941686494.
Dunno what's going on here.

best

Robert Dodier