integrate: is this question a bug?



Macsyma evaluates integrate(exp( sqrt(x)), x, 1, 5) without
asking any questions.

Barton

-----maxima-bounces at math.utexas.edu wrote: -----

>To: Edwin Woollett <woollett at charter.net>
>From: Raymond Toy <raymond.toy at ericsson.com>
>Sent by: maxima-bounces at math.utexas.edu
>Date: 07/18/2007 11:50AM
>cc: maxima mailing list <maxima at math.utexas.edu>
>Subject: Re: [Maxima] integrate: is this question a bug?
>
>Edwin Woollett wrote:
>> Hi Mailing List,
>>
>> Maxima asks an apparently meaningless question for the following
>definite integral:
>>
>> (using v. 12.0 with windows xp)
>>
>> (%i1) myint: integrate( exp( sqrt(x) ), x, 1, 5);
>>
>> Is  yx  positive or negative?
>>
>> p;
>> Is  yx - 1  positive, negative, or zero?
>>
>> p;
>>                                                           sqrt(5)
>> (%o1)                      2 (sqrt(5) - 1) %e
>>
>> ----------------------------
>> Are these questions a bug??
>
>I consider these bugs.  For the record, when doing definite integrals,
>maxima is trying a substitution here.  It uses the internal variable yx
>and wants to solve the equation yx = exp(sqrt(x)) for x.  I guess it
>needs to know the sign of yx to solve this.
>
>I don't know how to fix this problem.
>
>Does Macsyma have this problem?
>
>Ray
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