----Razafy Paul <paulrazafi at yahoo.fr> wrote: -----
> radcan will simplify them to zero I think!
Yes, radcan will simplify sqrt(3) * sqrt(17) - sqrt(51) to zero. But
radcan has to be used cautiously:
(%i75) eq : sqrt(a*b)= sqrt(a)*sqrt(b)$
(%i76) is(eq);
(%o76) false
(%i77) is(radcan(eq));
(%o77) true
(%i78) subst([a=-1,b=-1],eq);
(%o78) 1=-1
So radcan should not be used for general simplification (on constant
expressions such as sqrt(3) * sqrt(17) - sqrt(51), radcan is ok, I think).
Barton