In 11.3.0 for Microsoft Windows (64-bit) (March 7, 2018) writing:

Integrate[D[x*Sqrt[f[x]], x], x]

I would expect:


instead MMA fails to integrate.

Do I miss something?

  • 1
    $\begingroup$ Integrate internal code simply fails to recognize that the integrand is an exact derivative. $\endgroup$ – Daniel Lichtblau Jan 10 at 22:36
  • 1
    $\begingroup$ I think it comes down to simply evaluation order. Mathematica evaluates the derivative first then looks at the result. It does not have a build-in rule for Integrate[D[f[x],x],x]-> f[x]. I do not how to tell Mathematica not to evaluate the derivative first before trying to integrate the result. I tried this in Maple, and Maple seems to have such a rule build it. Screen shot: !Mathematica graphics btw, here is related question integrate-full-derivative $\endgroup$ – Nasser Jan 10 at 22:59
  • $\begingroup$ Ok, I think I understand, thank you very much! $\endgroup$ – TeM Jan 10 at 23:11

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.