Question

Choose the explicit and recursive formulas for the geometric sequence 45, 135, 405, 1215, 3645, .... PLEASE HELP ASAP

Answer 1

Answer:

Option (B)

Step-by-step explanation:

Given sequence is 45, 135, 405, 1215, 3645..........

Since it's a geometric sequence,

Common ratio of each successive term to the previous term

r = $\frac{135}{45}=3$

First term of the sequence 'a' = 45

Explicit formula of a geometric sequence will be,

$a_n=a(r)^{n-1}$

$a_n=45(3)^{n-1}$

Recursive formula of this sequence will be,

$a_n=3(a_{n-1})$, $a_1=45$

Therefore, Option (B) will be the answer.