Martin RUBEY <rubey@labri.fr> writes:
> I think that it is a bad idea that (rat)coeff returns zero, if it can't
> make the coefficient explicit, it should rather return 'ratcoeff...:
>
> (C1) ratcoeff((1+x)^k,x,2);
>
> (D1) 0
> (C2) ratcoeff(x^k,x,2);
>
> (D2) 0
But it does make the coefficient explicit (in the CRE representation
(1+x)^k is just a polynomial in the indeterminate (1+x)^k, but you
know that). IMHO the behaviour is perfectly consistent.
You could use POWERSERIES and dig out the coefficients with PART or
something.
Wolfgang