exp(x) automatically simplifies to %e^x, and %e^x * %e^y automatically
simplifies to %e^(x+y), so Maxima can't return the expression %e^x * %e^y.
It's unfortunate that 'integrate(%e^(x+y)*f(x),x) doesn't simplify to
%e^y*'integrate(%e^x*f(x),x).
Definitely a misfeature, maybe even a bug.
As a workaround, try the following:
(%i1) integrate(exp(x+y)*f(y),y);
(%o1) 'integrate(%e^(y+x)*f(y),y)
(%i2) ratsubst(expx,exp(x),%o1);
(%o2) expx*'integrate(%e^y*f(y),y)
(%i3) subst(exp(x),expx,%o2);
(%o3) %e^x*'integrate(%e^y*f(y),y)
Does this solve your problem?
-s
On Wed, Mar 14, 2012 at 11:32, Aleksas Domarkas <aleksasd873 at gmail.com>wrote:
> How factor exp(x+y) ?
>
> For examaple, I want
> integrate(exp(x+y)*f(y),y) convert to
> exp(x)*integrate(exp(y)*f(y),y).
>
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