rational denominator

[Ralf Hemmecke]

Hi,

I know in general it is problematic for complex numbers, but does
FriCAS have a function that transforms

r := sqrt(3/5)

into sqrt(15)/5. I would like to have integers instead of rational
numbers under the sqrt.

Ralf

[Franz Lehner]

Hi,

On Fri, 8 Mar 2024, Ralf Hemmecke wrote:
> FriCAS have a function that transforms
>
> r := sqrt(3/5)
>
> into sqrt(15)/5.

(1) -> ratDenom sqrt(3/5)

+-+ +-+
\|3 \|5
(1) --------
5
Type: AlgebraicNumber

Franz

[Ralf Hemmecke]

That is strange. I tried that before I asked.

%%%% (1) -> ratDenom sqrt(3/5)

+-+
|3
(1) |-
\|5
Type: AlgebraicNumber

You must have a different version than me.

Ralf

[Franz Lehner]

On Fri, 8 Mar 2024, Ralf Hemmecke wrote:
> You must have a different version than me.

Version: FriCAS 2023-06-17
Timestamp: Do 09 Nov 2023 14:01:26 CET

Franz

[Waldek Hebisch]

On Fri, Mar 08, 2024 at 03:28:49PM +0100, Ralf Hemmecke wrote:
> That is strange. I tried that before I asked.
>
> %%%% (1) -> ratDenom sqrt(3/5)
>
> +-+
> |3
> (1) |-
> \|5
> Type: AlgebraicNumber
>
> You must have a different version than me.

FriCAS used to automatically split roots. To get the
above now do

rootSplit(r)

note that AlgebraicNumber automatically removes root from the
donomiantor. You need ratDenom for Expression.

I would like to add more functions doing root simplifications,
in particular replacing dependent roots by independent ones,
changing expression so that there are only integer/polynomial
roots and number of independent roots do not increase, etc.

--
Waldek Hebisch