If p, q are roots of x2+px+q=0, then
p = 1
p = 1 or 0
p = – 2
p = – 2 or 0
We have p + q = – p, pq = q
As pq = q,
we get q(p – 1) = 0
⇒ q = 0 or p = 1
If q = 0, we get p = 0
If p = 1, we get p + q = – p⇒ q = – 2.
Thus, p = 1 or p = 0.