If A, G and H are respectively the A.M., the G.M. and the H.M. between two positive numbers a and b, then the correct relation is
(4)
For positive numbers a and b,
A=a+b2, G=ab and H=2aba+b
Now, AH=a+b2(2aba+b)=ab=G2
∴ The correct relation is, G2=AH