Subject: Simplifications of 3*sqrt(2)/sqrt(3)/sqrt(6)
From: Robert Dodier
Date: Fri, 3 Jul 2009 11:48:43 -0600
On 7/2/09, Raymond Toy <toy.raymond at gmail.com> wrote:
> Not sure. The other examples you presented are probably what I would
> like. But I'm not so sure that I would want sqrt(6) to be factored into
> sqrt(2)*sqrt(3). But I would like sqrt(6)/sqrt(3) to be simplified to
> sqrt(2). Perhaps these are conflicting desires on my part.
FWIW I don't want to see sqrt(6) => sqrt(3)*sqrt(2) but I do want to
see (somehow) sqrt(6)/sqrt(3) => sqrt(2).
> And I think always calling factor for these cases may not be such a good
> idea. What if the number is the product of two fairly large primes or
> even a prime? Maxima will spend a lot of time trying to find the factors.
I don't have a very strong opinion about it, but I am leaning towards
omitting the call to factor from simplification, and moving it into
radcan or something like that, on the general theory that we should
try to avoid potentially expensive operations in simplification
(in the built-in simplification, at least). A user could still get the
result of factorization by an explicit call to radcan (or whatever function).
best
Robert Dodier