Question

If the first and the third terms of a G.P. are 2 and 8 respectively, find its second term.

Answer 1

Let the first term of the G.P. be a and its common ratio be r.

∴ 1^st term = a = 2

And 3^rd term = 8 `=>` ar² = 8

Now, `(ar^2)/a = 8/2`

`=>` r² = 4

`=>` r = 2

When a = 2 and r = 2

2^nd term = ar = 2 × 2 = 4