# How do you tell whether the sequence -8, 24, -72.... is arithmetic, geometric, or neither?

##### 1 Answer

Oct 22, 2015

#### Answer:

The sequence is a geometric sequence.

#### Explanation:

- Checking if it a geometric sequence :

In a geometric sequence a common ratio

**Since #r_1= r_2# this shows that the ratio maintained is constant, so the sequence is geometric in nature.**

- Checking if the sequence is an arithmetic progression:

For an arithmetic progression a common difference

Since