Q17 of 104 Page 468

If a, b, c, d are in GP, then prove that

are in GP


To prove: are in GP.


Given: a, b, c, d are in GP


Proof: When a,b,c,d are in GP then



From the above, we can have the following conclusion


⇒ bc = ad … (i)


⇒ b2 = ac … (ii)


⇒ c2 = bd … (iii)


Considering


=


=


From eqn. (i) , (ii) and (iii)


=


=


=


From the above equation, we can say that are in GP.


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