Question

This geometric sequence?
What is the explicit formula for
8, 4, 2, 1, ...

Answer 1

D

Explanation:

the first term is 8, the ratio is 1/2 ( 8*1/2 = 4, 4*1/2 = 2, 2*1/2 = 1)

the formula for an explicit geometric formula is :

`a_(n) = a_(1) * r^((n-1))`

plug in your numbers :

`a_(n) = 8 * ((1)/(2)) ^((n-1))`