00:01
Suppose we have a sequence that starts 0 .4, then 0 .04, then 0 .004, and so on.
00:08
Let's determine what its eighth term is going to be.
00:11
Well, for a sequence like this, we first need to figure out the initial term and the common ratio.
00:16
Initial term is pretty easy, that's just 0 .4.
00:18
Common ratio is a little bit more difficult.
00:20
This is equal to any term divided by the previous term, such as 0 .004 over 0 .04.
00:28
And it will be the same for any pair of consecutive numbers, so it will also be the same as .04 over 4.
00:35
All right, so with this in mind, we can easily see that it is equal to 0 .1.
00:41
That is the common ratio between these terms.
00:43
Now we can use a formula out of the book to determine the eighth term...