# Ticket #10868(closed defect: fixed)

Opened 2 years ago

## A wrong (easy) limit

Reported by: Owned by: jvarona burcin major sage-5.0 calculus mjo Fixed upstream, in a later stable release. Aly Deines Michael Orlitzky sage-5.0.beta3 #12094

### Description

If we define f(n)=2+1/factorial(n) the answer of sage for limit(1/f(n),n=oo) is 1, that is clearly wrong. However, limit(f(n),n=oo) gives the answer 2, that is correct.

I have seen this problem in (at least) sage 4.6 and sage 4.6.2, in several kind of computers.

## Change History

### comment:1 Changed 2 years ago by kcrisman

• Report Upstream changed from N/A to Reported upstream. Little or no feedback.
• Authors jvarona deleted

This is in Maxima.

```sage: maxima_console()
Maxima 5.22.1 http://maxima.sourceforge.net
using Lisp ECL 10.4.1
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i3) limit(2+1/factorial(n),n,inf);
(%o3)                                  2
(%i4) limit(1/(2+1/factorial(n)),n,inf);
(%o4)                                  1
```

This is still present in the latest Maxima. See  this report.

### comment:2 Changed 2 years ago by kcrisman

• Report Upstream changed from Reported upstream. Little or no feedback. to Fixed upstream, but not in a stable release.

This report suggests it is fixed in the latest upstream. This would need a patch to verify, once we would update Maxima to that release.

### comment:3 Changed 18 months ago by mjo

• Dependencies set to #12094
• Report Upstream changed from Fixed upstream, but not in a stable release. to Fixed upstream, in a later stable release.

This is fixed in stable maxima 5.24.0:

```sage: f(n)=2+1/factorial(n)
sage: limit(1/f(n),n=oo)
1/2
sage: limit(f(n),n=oo)
2
sage: maxima.version()
'5.24.0'
```

### Changed 16 months ago by mjo

Add a doctest for this result. Apply on top of #11483 and #11591 to avoid fuzz.

### comment:4 Changed 16 months ago by mjo

• Status changed from new to needs_review
• Authors set to Michael Orlitzky

Maxima 5.24 has a positive review now, so here's a doctest. The file maxima_lib.py gets some new doctests in #11483 and #11591 so to avoid fuzz, apply on top of those (we don't require either of them for the result, though).

### comment:5 Changed 16 months ago by aly.deines

• Status changed from needs_review to positive_review
• Reviewers set to Aly Deines

### comment:6 Changed 16 months ago by jdemeyer

• Status changed from positive_review to closed
• Resolution set to fixed
• Merged in set to sage-5.0.beta3
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