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interesting find, hard integral
Posted:
Oct 9, 2017 1:48 AM


fyi;
This integral is hard
Integrate[(E^(x/(2 + x^2))*(2 + 2*x + 3*x^2  x^3 + 2*x^4))/(2*x + x^3),x]
It is Hebisch Problems #3. Maple, Rubi and Mathematica can not solve it:
https://www.12000.org/my_notes/CAS_integration_tests/reports/rubi_4_11/test_cases/Independent_test_suites/Hebisch_Problems/resu3.htm#3
FriCAS can. But I just found out, that mathematica version 2.2 also can also solve it and it gives same answer as Fricas.
Mathematica version 2.2 is from 1993 !
Here is screen shot, sidebyside, version 2.2 and version 11.2 of Mathematica, showing 2.2 is able to solve this but not 11.2.
https://www.12000.org/tmp/hard_integral/22_vs_11_2.png
I just find this amazing and funny also and thought to share it.
How can such an old version of Mathematica solve an integral which a version that is 25 years later is not able to?
I found this, as I was trying to see if I can run the CAS integration tests on V2.2 of Mathematica.
Nasser



