% polys - useful polynomial functions

format compact
syms s;

pp = (s-1)*(s+3)*(s-(1+j))*(s-(1-j))
p = expand (pp) % convert pole form to coefficient form
pf = factor(p)  % convert coefficient form to pole form

pc = [1 0 -5 10 -6]
pr = roots(pc)  % find roots of polynomial
pcr = poly(pr)  % find polynomial from roots

% Find and evaluate symbolic roots (limited by order of poly)
ps = solve ('s^4-6-5*s^2+10*s=0')
pss = solve ('s^4-K-5*s^2+10*s=0')
K = 6;
eval(pss)