"Fabrizio Caruso" wrote:
> I am looking for a command that collects all the terms
> of a polynomial w.r.t. a variable, i.e. it writes the polynomial
> as a sum of monomials with increasing/decreasing powers of
> a given variable.
> Is there one?
you may find a definition like this one useful:
rewriteAsPolynomialIn (p, t) :=
block ([expanded, degreeInT, result],
expanded : expand(p),
degreeInT: hipow(expanded, t),
result : 0,
for idx : 0 thru degreeInT do
result : result + t^idx*ratcoeff(expanded, t, idx),
result
);
Usage:
t : (x+1)^4 + a*(x+1)^2+b*(x+1)+c;
rewriteAsPolynomialIn(t, x);
Are there better solutions?
Greetings, Boris