Integration by parts.



-----maxima-bounces at math.utexas.edu wrote: -----

>I?wrote?a?small?integration?by?parts?function:

>It?seems?to?work?OK,?but?my?question?is.?Does?Maxima?already?have
>something?like?this??

Yes, look at /maxima/share/integration/bypart.mac (undocumented, I think). 
See also, antidiff:

?(%i53) load(antid)$

?(%i54) antidiff(f(x)*diff(g(x),x),x,g(x));
?(%o54) f(x)*g(x)-integrate(g(x)*('diff(f(x),x,1)),x)

Finally, maybe you could modify your code to respect definite integration:

?(%i64) integrate (f(x)*diff(g(x),x),x,0,1);
?(%o64) integrate(f(x)*('diff(g(x),x,1)),x,0,1)

?(%i65) ibyparts(%,f(x),x);
?(%o65) f(x)*g(x)-integrate(g(x)*('diff(f(x),x,1)),x)

--Barton