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Question
If a, b and c are in G.P., prove that : log a, log b and log c are in A.P.
Solution
Here, a, b, c are in G.P.
`=>` b2 = ac
Taking log on both sides, we get
log(b2) = log(ac)
`=>` 2log b = log a + log c
`=>` log b + log b = log a + log c
`=>` log b – log a = log c – log b
`=>` log a, log b and log c are in A.P.
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