Geometric
Recursive Models
Another way to represent a geometric sequence is a recursive function, or any model that demonstrates how to find the next term in a sequence. In order to find the next term, an, multiply the previous term, an-1, by the common ratio. An example of a recursive model is: an = r · an-1 . This formula is also known as the recursive formula and is used when previous terms and the common ratio are known values.
Example Write a recursive function to model the following sequence:
3, 6, 12, 24, 48 …
Step 1. Determine the common ratio.
The common ratio is two, r = 2.
Step 2. Write a recursive model and reference the first term.
