4 2 2 p - 2*p *q + q
p^4 - 2*p^2*q + q^2
/ ___\ / ___\ 1*\p + \/ q /*\p - \/ q /
(1*(p + sqrt(q)))*(p - sqrt(q))
p^4 + q^2 - 2.0*q*p^2
2 / 2 \ \p - q/
(p^2 - q)^2