Question

How do you find the first 4 terms of a geometric sequence with a first term of 2 and a common ratio of 4?

Answer 1

`"First four terms are " 2, 8, 32, 128`

Explanation:

Given `"First Term " a = 2, "Common ratio " r = 4`

`n^(th) term " " a_n = a * r^ (n - 1)`

Hence, `a_2 = a * r^(2 - 1) = a r = 2 * 4 = 8`

`a_3 = a * r^(3 - 1) = a r^2 = 2 * 4^2 = 32`

`a_4 = a * r^(4 - 1) = a r^3 = 2 * 4^3 = 128`

`a_5 = a r^4 = 2 * 4^4 = 512`