Question

Find an explicit rule for the nth term of the sequence.

1, 3, 9, 27, ...
an = 1 • 3n + 1
an = 3 • 1n - 1
an = 1 • 3n - 1
an = 1 • 3n

Answer 1

hello ;
an = 1 • 3n - 1

Answer 2

Option C is the correct answer.

Explanation:

1, 3, 9, 27, ...

This is an example of Geometric progression.

First term, a = 1

Common ratio, r = 3

We have n th term of GP

`a_n=ar^(n-1)`

Substituting

`a_n=ar^(n-1)=1* 3^(n-1)`

Option C is the correct answer.