If a,b,c are in G.P.,then the equations ax2+2bx+c=0 and dx2+2ex+f=0 have a common root if da′eb′fc are in
(i) A. P.
(ii) G.P.
(iii) H.P.
(iv) None of these.
Another form :
If ax2+2bx+c=0 and px2+2qx+r=0 have a common root and ap′bq′cr in A.P. then prove that p,q,r are in G.P.