Hi,
I was trying to calculate the following double integral and I thought I
had made the proper assumptions:
assume(H>0);assume(d>0);assume(x>=0);assume(H>x);assume(H>d);assume(y>0);
'integrate('integrate(gam*(y-H+d),y,H-d,sqrt(H^2-x^2)),x,0,sqrt((H^2-(H-d)^2)));ev(%,nouns);
However I get the following error message:
defint: upper limit of integration must be real; found sqrt(H^2-(H-d)^2)
-- an error. To debug this try: debugmode(true);
Now, if I add the assumption: H^2>(H-d)^2
then, the double integral works fine.
Question: shouldn't Maxima be able to conclude that H^2>(H-d)^2, given
the assumptions:
H>0, d>0, H>d ?
Not a major issue, except that it took me about 15 mins. to figure it out.
--
Gilberto E. Urroz, Ph.D., P.E.
Associate Professor
Dept. of Civil& Environmental Engineering and
Utah Water Research Laboratory
Utah State University
Logan, UT 84322-4110
ph. 435-797-3379
fax 435-797-1185
gilberto.urroz at usu.edu
http://www.neng.usu.edu/cee/faculty/gurro/