Question

Write a RECURSIVE and EXPLICIT model for the following geometric sequence. 3, 15, 75, 375, 1875, ...

Answer 1

Answer:

Step-by-step explanation:

Common ratio (r) = 2nd term / 1st term = 15/3 = 5

Recursive formula:

$a_{n}=a_{n-1}*r \\\\a_{n}=a_{n-1}*5\\=5a_{n-1}$

Explicit formula:

a = first term = 3

$a_{n}=ar^{n-1}\\\\a_{n}=3*(5)^{n-1}$