Each week Manhattan GMAT posts a GMAT question on our blog and follows up with the answer the next day. Are you up for the challenge?
If there is exactly one root of the equation x2 + ax + b = 0, where a and b are positive constants, what is b in terms of a?
(A) a/2
(B) a
(C) 3a/2
(D) a2/2
(E) a2/4