# How do you find the common ratio of -1/4,1/8,-1/16,1/32,...?

Aug 1, 2018

$- \frac{1}{2}$

#### Explanation:

How do we get from $- \frac{1}{4}$ to $\frac{1}{8}$? Notice our sign changed, so we multiplied by a negative.

One way to get from $- \frac{1}{4}$ to $\frac{1}{8}$ is to multiply by $- \frac{1}{2}$.

How do we get from $\frac{1}{8}$ to $- \frac{1}{16}$? We can multiply by $- \frac{1}{2}$ again.

What about from $- \frac{1}{16}$ to $\frac{1}{32}$? We can multiply by $- \frac{1}{2}$.

Notice, to get to each successive term, we are multiplying by $- \frac{1}{2}$. This is our common ratio.

Hope this helps!