The harmonic mean of $ \frac{a}{1-a b} $ and $ \frac{a}{1+a b} $ is

$ \frac{a}{\sqrt{1-a^{2} b^{2}}} $

JEE MATHEMATICS MCQ: SEQUENCE OF SERIES

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Application +4 | -1

The harmonic mean of

\frac{a}{1-a b}

and

\frac{a}{1+a b}

View answer and explanation

Correct option: C

a

Option C (

a

) is correct because when the harmonic mean is calculated between the two given expressions, the result simplifies to 'a'.

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