If A1,A2 be two AM'x and G1,G2 be two GM's between a and b, then find the value of A1+A2G1G2
a, A1,A2 b are in A.P.
A1−a=A2−A1=b−A2 ......... (1)
and (a, G1, G2,) b are in G.P.
G1=√aG2,G2=√G1b
⇒G1G−2=sqrtabG1G2
⇒√G1G2=√ab
⇒G1G2=ab ........... (2)
From equation (1),
2A1=A2+a
2A2=A1+b
Adding these two,
2(A1+A2)=(A1+A2)+a+b
A1+A2=a+b
⇒A1+A2G1G2=a+bab