Re : how to handle roots of unity symbolically ?



On 2012-11-23, Stavros Macrakis <macrakis at alum.mit.edu> wrote:

> (%i2) p: x^12-1$
> (%i3) factor(p);
> (%o3) (x-1)*(x+1)*(x^2+1)*(x^2-x+1)*(x^2+x+1)*(x^4-x^2+1)
> (%i4) tellrat(last(%));

Stavros, why did you factor p and apply tellrat to only the last factor?
That seems to have a different effect compared to tellrat(p).

Is there some unstated assumption in tellrat about p? Maybe we need to
add something to the documentation -- ? tellrat says only that p is a
polynomial with integer coefficients.

best

Robert Dodier