Now that we know how these geometric guys work, we won't have to do the table thing anymore!
What are all the pieces?
Here's the general formula:
Given a geometric sequence
with a ratio of r, the nth term is

Let's try it!
What's the 23th term of this sequence?
Find the ratio:
So...
By the way, these
( )
are really important if your ratio is negative!
So, be careful!
TRY IT:
Find the formula for the nth term, then use it to find the 11th term of this sequence