integrating trig functions with large constants, exponent out of range
Subject: integrating trig functions with large constants, exponent out of range
From: Daniel Lakeland
Date: Fri, 5 Jan 2007 15:51:45 -0800
On Sat, Jan 06, 2007 at 01:10:07AM +0200, Neilen Marais wrote:
> Hi
>
> I get the following problem:
>
> I tried reducing the error:
>
> (%i9) integrate(%i*sin(34037595938027*x3)*x3, x3);
>
> but had to interrupt it since it seemed to take forever. I found that
> the integration time is dependent on the size of the constant in the
> expression. integrate(%i*sin((3*x3))*x3, x3) happens fast,
> integrate(%i*sin((30000*x3))*x3, x3) takes several seconds etc.
This executes in no time flat for me on windows stock maxima 5.10.0 in
GCL.
****** It also gives a wrong answer!!! ******
(%i1) integrate(%i*sin(34037595938027*x3)*x3, x3);
%i (sin(2 x3) - 2 x3 cos(2 x3))
(%o1) -------------------------------
4
(%i2) diff(%,x3);
(%o2) %i x3 sin(2 x3)
--
Daniel Lakeland
dlakelan at street-artists.org
http://www.street-artists.org/~dlakelan