Find the values of p for which the equation x2 – (p – 2)x + 2p + 1 = 0
-
A.
(21, 0) -
B.
(0, 12) -
C.
(1, 2) -
D.
(3, 4) -
E.
(4, 5)
Correct Answer: Option B
Explanation
Equal roots implies b2 – 4ac = 0
a = 1b = – (p – 2), c = 2p + 1
[-(p – 2)]2 – 4 x 1 x (2p + 1) = 0
p2 – 4p + 4 – 4(2p + 1) = 0
p2 – 4p = 4 – 8p – 4 = 0
p2 – 12p = 0
p(p – 12) = 0
p = 0 or 12