Question

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

Answer 1

Given: The first and the third terms of a GP are 2 and 8

To find: The second term?

Solution:

• Now we have given that the first and the third terms of a Geometric Progression are 2 and 8 respectively.

• The terms of Geometric Progression are:

                   a , ar , ar^2

• So:

                   a = 2 and ar^2 = 8

• Putting a = 2 in ar^2, we get:

                   (2)r^2 = 8

                   r^2 = 4

                  r = ±2

• If r = 2, then the series will be:

                   2 , 4 , 8

• If r = -2, then the series will be:

                   2 , -4 , 8

Answer:

            So the second term of the series will be ±4.