Semyon Glazyrin wrote:
> Hello!
>
> When I try to integrate one simple expression maxima asks me about
> sign of one subexpression. But I think in this case integral limits
> answer the question:
>
> (%i2) assume(a>0,b>0);
> (%o2) [a > 0, b > 0]
> (%i3) integrate(sqrt(a/x-b),x,0,a/b);
> Is b x - a positive, negative, or zero?
>
> n; %pi a
> (%o3) ---------
> 2 sqrt(b)
>
> Does maxima do such type of checks?
>
sometimes. if you leave out all assumptions it behaves differently, so
it uses them for something.
if you say assume(b*x-a<0) then it does not ask the question, and just
gives the answer.
Which behavior represents a bug is not entirely clear. Since x is a
global variable in the "assume"
and x is a (presumably different) bound variable in the integration,
should the assumption have
any effect? On the other hand, shouldn't the integration program figure
more of this out itself?
RJF
> thanks,
> Semyon.
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