# Interface problem, integrate with giac

Is this a known issue? Using sage 8.3 beta 6.

I reported this at https://trac.sagemath.org/ticket/25626

sage: var('t')
sage: integrate(exp(t)/(t + 1)^2,t,algorithm="giac")
undef


But using giac directly, it can integrate it with no problem

>giac
// Using locale /usr/share/locale/
// en_US.utf8
// /usr/share/locale/
// giac
// UTF-8
// Maximum number of parallel threads 8
(c) 2001,2017 B. Parisse & others
Homepage http://www-fourier.ujf-grenoble.fr/~parisse/giac.html
Released under the GPL license 3.0 or above
May contain BSD licensed software parts (lapack, atlas, tinymt)
-------------------------------------------------
0>> integrate(exp(t)/(t + 1)^2,t)
(t*Ei(t+1)+Ei(t+1)-exp(1)*exp(t))/(t*exp(1)+exp(1))
// Time 0.01
1>>


So why did sage return udef for this result?

edit retag close merge delete

In 9.3.beta5, giac doesn't solve it when used through integrate :

sage: integrate(exp(t)/(t+1)^2,t, algorithm="giac")
integrate(e^t/(t + 1)^2, t)
sage: integrate(exp(t)/(t+1)^2,t)
-e^(-1)*exp_integral_e(2, -t - 1)/(t + 1)
sage: integrate(exp(t)/(t+1)^2,t, algorithm="sympy")
integrate(e^t/(t + 1)^2, t)
sage: integrate(exp(t)/(t+1)^2,t, algorithm="fricas")
((t + 1)*Ei(t + 1) - e^(t + 1))*e^(-1)/(t + 1)
sage: mathematica.Integrate(exp(t)/(t+1)^2,t)
-(E^t/(1 + t)) + ExpIntegralEi[1 + t]/E


But does when used directly :

sage: %giac integrate(exp(t)/(t + 1)^2,t)
(t*Ei(t+1)+Ei(t+1)-exp(1)*exp(t))/(t*exp(1)+exp(1))


HTH,