more three problems...



Rainer Joswig wrote:
> In article <463BC69B.50901 at gmail.com>,
>>
>> Try float(atan(2/5-%i/5)).
>>
>> The reason I'm asking is that acot(x) is evaluated via atan(1/x).  If
>> atan(1/x) returns nil, a domain error is signaled.
>>
>> Ray
> 
> 
> (%i1) float(atan(2/5-%i/5));
> 
> (%o1)          - 1.0 (.1732867951399863 %i - .3926990816987241)
> 

Hmm.

Ok.  Can you try the original problem again, but this time, trace 
cl:atan?  (Something like ":lisp (trace cl:atan)").

Ray