Q.

The A.M. of the roots of a quadratic equation is A and G.M. of its roots is G. The quadratic equation is

1 x2+Ax+G2=0  
2 x2+2Ax+G2=0  
3 x2-Ax+G2=0  
4 x2-2Ax+G2=0  

Ans.

(4)

Let the equation be x2-(α+β)x+αβ=0  has roots α,β.

Also,  A=α+β2,  G=αβ⇒  α+β=2A,  αβ=G2

∴  The required equation is x2-2Ax+G2=0