a, b, c are positive real numbers forming a. G.P. If ax2 + 2bx + c = 0 and dx2 + 2ex + f = 0 have a common root, then d/a, e/b, f/c are in
(A) A.P.
(B) G.P.
(C) H.P.
(D) of these
Correct Option :- (A)
Explanation :-
For first equation D = 4b2 – 4ac = 0 (as given a, b, c are in G.P.). The equation has equal roots which are equal to –b/a each. Thus, it should also be the root of the second equation.
