Question

What is the explicit formula for this sequence?

5, 10, 20, 40, 80, 160,...
O A. an = 5 + 5(n-1)
O B. an = 2(5)(n-1)
O c. an = 5(2)"
D. an = 5(2)(n = 1)

Answer 1

Explanation:

The above sequence is a geometric sequence

For an nth term in a geometric sequence

`a(n) = a ({r})^(n - 1)`

where

n is the number of terms

a is the first term

r is the common ratio

From the question

a = 5

r = 10/5 = 2

Therefore the explicit formula for this sequence is

`a(n) = 5( {2})^(n - 1)`

Hope this helps you