Question

If p and q are the roots of the equation x² + px + q = 0, then
(a) p = 1, q = –2 

(b) p = 0, q = 1

(c) p = –2, q = 0 

(d) p = –2, q = 1.

Answer 1

(a) : Given S = p + q = – p and product pq = q
=> q(p – 1) = 0
=> q = 0, p = 1
Now If q = 0 then p = 0 => p = q
If p = 1, then p + q = – p
q = – 2p
q = – 2(1)
q = – 2
=> p = 1 and q = – 2