00:01
You want to investigate some sums.
00:06
So this one, this is what's called a telescoping series.
00:16
So if it is an infinite series, but it doesn't tell us what the limits on the series are.
00:27
So we don't know that for sure, but assuming it's an infinite series, it does converge and our nth term looks like this.
00:41
But the thing is, is that in a telescoping series, a lot of stuff cancels.
00:48
And the only thing you're left over with is the first thing.
00:56
So the actual value of the sum depends on our starting point, which we are not given.
01:05
Is it zero, one, two, three, four, five, whatever.
01:09
Okay, so it's hard to write down the sum without knowing the starting point.
01:23
So i'm gonna write a starting point in, i'm gonna call it r, and then the sum is one over r plus one.
01:59
Now we want to do this series.
02:00
Again, we're not given the limits.
02:02
I'm assuming it's an infinite series, because otherwise it automatically converges.
02:08
Supposed to use the integral test.
02:22
What matters for the integral test is that the actual term is decreasing in size, which it is.
02:35
So we're okay there...