poly - polynomial definition
If a is a matrix, p is the characteristic polynomial i.e. determinant(x*eye()-a), x being the symbolic variable.
If v is a vector, poly(v,"x",["roots"]) is the polynomial with roots the entries of v and "x" as formal variable. (In this case, roots and poly are inverse functions).
poly(v,"x","coeff") creates the polynomial with symbol "x" and with coefficients the entries of v (v(1) is the constant term of the polynomial). (Here poly and coeff are inverse functions).
s=poly(0,"s") is the seed for defining polynomials with symbol "s".
s=poly(0,"s");p=1+s+2*s^2; A=rand(2,2);poly(A,"x")