Am Samstag, den 26.02.2011, 18:05 -0500 schrieb Stavros Macrakis:
> Dieter,
>
>
> I recall that you've worked on the simplification of products of
> radicals in the past.
>
>
> On the other hand, I don't remember if there was ever any discussion
> of the case sqrt(6)/sqrt(2). In current Maxima, this isn't simplified
> by the general simplifier or by ratsimp -- you have to use
> rootscontract or radcan. I don't know if it's always been like this
> or not, but it is a surprise nonetheless.
>
>
> I think it would be desirable for x^a*y^-a (where x and y are integer
> constants) to simplify in the general simplifier to the same thing as
> (x/y)^a. For that matter, the more general cases 18^(3/5)*48^(-4/5)
> => 3^(2/5)/2^(13/5) and even 18^(3/5)*48^(-3/7) => 3^(27/35)/2^(39/35)
> are straightforward enough to handle (cf. radcan). There may be an
> argument that this last case is too radical change in form, and it
> will surprise our users, but then 18^3/48^4 already gets simplified to
> 9/8192.
Yes, I have written code to simplify expressions like sqrt(6)/sqrt(2).
This can be done in the main simplifier. I have done it because of the
bug report ID: 1639678 "3*sqrt(2)/sqrt(3)/sqrt(6) != 1"
I will have a look to find the piece of code again.
Dieter Kaiser