If a, b, c are in hp, then b is related with a and c as _________
(a) 2(^1⁄b) = (^1⁄a + ^1⁄c)
(b) 2(^1⁄c) = (^1⁄b + ^1⁄c)
(c) 2(^1⁄a) = (^1⁄a + ^1⁄b)
(d) None of the mentioned
I had been asked this question in my homework.
The question is from Harmonic Sequences in chapter Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics