Express r in terms of p and q, if the roots of the equation x2+px+q=0 are α,β and the roots of the equation
x2−rx+s=0 are α4,β4
(p2−2q)2 - 2q2
α+β=−p, αβ=q
α4+β4=r
=(α2+β2)2 - 2α2β2
=((α+β)2−2αβ)2−2α2β2
r=(p2−2q)2−2q2