Question

For the following geometric sequence find the explicit formula. {12, -6, 3, ...}

Answer 1

12(-1/2) to the exponent n-1

Answer 2

`a_n=12 (-0.5)^(n-1)`

Explanation:

Given geometric sequence ,

12, -6, 3, ...........

First term, a = 12,

Common ratio,

`r = (-6)/(12)=-0.5`

Since, the explicit formula of a Geometric sequence is,

`a_n=ar^(n-1)`

Hence, the explicit formula of the sequence is,

`a_n=12 (-0.5)^(n-1)`