00:01
So this kind of problem is trying to get you to think about why a geometric sequence when the ratio is less than one or greater than negative.
00:09
When it's a little bit of a small value, why does that, how does that change the sequence? and i like to go into discussion about this because you have two different types of formulas for a geometric sequence.
00:21
You have for the sum of a geometric series.
00:24
I mean, for a finite sequence, you have this formula and for an infinite sequence, of this formula is much more simplified.
00:31
It really just drops the numerator from it.
00:33
And the reason why is because a infinite sequence will eventually max out.
00:40
Okay, and i'm going to kind of show you with some examples, but that could be.
00:43
So a finite, as a geometric series that's finite, is when the ratio, the absolute value of the ratio is greater than one.
00:51
So let's say we had a sequence such as 2, 4, 8, 16, 32.
00:58
See how those numbers are the number numbers are key, they keep getting larger, right? an infinite sequence is when the absent value of the ratio is less than one.
01:06
It's a small value.
01:08
So that same sequence starting at two, instead of it going times two to four, let's do times a half.
01:14
So down to one, a half, a fourth, and then an eighth, and a sixteenth.
01:21
Like they keep getting smaller, but that one keeps getting larger...