Re: [Maxima-bugs] [ maxima-Bugs-1281737 ] limit(atan(x)/(1/exp(1)-exp(-(1+x)^2)),x,inf,plus) - wrong



Milan Lukic wrote:
>>Could be.  I'd have to read the thesis again.  I also guess that if
>>that's true, whoever added the code to convert atan to log didn't know
>>that either.
>>
>>I also never heard of tlimit.  In this particular case
>>
>>tlimit(atan(x)/(1/exp(1)-exp(-(1+x)^2)),x,inf,plus)
>>
>>returns 0.  Probably because 
>>
>>taylor(atan(x)/(1/exp(1)-exp(-(1+x)^2)),x,inf,1)
>>
>>returns
>>
>>0 + ...
>>
> 
> I get a QUOTIENT by ZERO error with either tlimit or taylor, and the
> same on Maxima-5.9.1 and the current release candidate!
> How does Maxima do taylor at infinity? I have a feeling that you just
> discovered yet another problem that maxima does not handle correctly.

Which lisp?  I ran this with the current CVS code, using cmucl on Mac OS
X and Solaris.

I'm pretty sure taylor can do series at infinity.  1/(1-x) seems to work.

I think I looked at the taylor code once.  If it's what I remember, I
don't plan on looking at it again. :-(

Ray