Unfortunately, sqrt(x^2)=abs(x) is wrong. It is well known that there
are 2 square roots, which might in this case be written as {x, -x}.
Maxima does not have an effective way of dealing with {x, -x},
Radcan, as should be indicated in the documentation, picks one of them.
RJF
Valery A. Lovchikov wrote:
> Hi!
>
> f:2*((u-cos(b))^2-u^2+2*cos(b)*u)+2*u^2-4*cos(b)*u;
> x:factor(expand(f));
> err:sqrt(factor(expand(f)))-radcan(sqrt(f));
> /* sqrt(x^2)=abs(x), not sqrt(x^2)=x */
>
> Please corect.
>
> Truly yours,
> Valery Lovchikov
>
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