seen first in 11.1.1, Fixed in 11.2

What is going on here? In version 11.1.1 on windows 7

Mathematica graphics

Using Version 11.0.1 also on windows 7

Mathematica graphics

Source code

ClearAll[x, n, c, a ,b]
Integrate[(a + b*(c*x^n)^(2/n))^3, x]

Why does Mathematica give 1/0 now in the latest update? Do you think this is a new bug?

  • $\begingroup$ If you want, you can try traceView2[ Trace[Integrate[(a + b*(c*x^n)^(2/n))^3, x], TraceInternal -> True]] to find out where things go wrong. $\endgroup$ – QuantumDot Jul 1 '17 at 20:49
  • $\begingroup$ Slightly more minimal example triggering the bug: Integrate[(1 + (x^n)^(-n^(-1)))^2, x] $\endgroup$ – QuantumDot Jul 1 '17 at 21:02
  • $\begingroup$ @QuantumDot Yes, I found many more little simpler examples. This one also triggers it: Integrate[(a+(c*x^n)^(2/n))^3,x] but changing to Integrate[(a+(c*x^n)^(1/n))^3,x] and error goes away! I just copied the one from the file I was running and posted that. I get more integrals now with same error. But I am sure they are all due to same bug. $\endgroup$ – Nasser Jul 1 '17 at 21:07

Obviously, this is a bug. It actually dates to 11.1.0. I checked with the relevant developer. We have a fix in our internal development build, and we'll try to get it into the next release.

This is one of those funny cases where a bugfix elsewhere caused a slightly different path to be traversed inside Integrate, and that path was missing a check for division by zero.


fyi; This bug is now fixed in 11.2. Thank you WRI

Mathematica graphics


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.