00:01
So the sequence we were looking at today is a sub n equals 1 plus 0 .5n, sorry, 1 plus 0 .5 over n, all raise to the power n.
00:14
Excuse me.
00:16
And so today i'll be using geogrebrae calculus calculator, to evaluate and analyze the sequence.
00:24
If you're using your own calciculator, the documentation for functions may be different.
00:29
So you might not be able to do exactly what i do here.
00:34
But nevertheless, so first we have to plot the first 25 terms.
00:38
So let's see.
00:40
We're going to label l1.
00:44
And so for the sequence function, first i'm just going to get the whole numbers that we can, so we can plot the sequence against it.
00:51
So our function will be n, and variable n, starting at 1 and ending at 25.
00:58
So as you can see, this gives us a sequence of the whole numbers.
01:02
Now to get our actual sequence, once again use the sequence function with our expression.
01:15
This is the formula for the sequence in the variable n, start terms, or starting at n equals 1, ending at n equals 25, and that gives us our sequence here.
01:28
And then finally we have to plot the two together to get it on our graph, and here it is.
01:37
So you can see that it starts off at 1 .5, then it starts getting a little bigger, bigger.
01:46
And then it's hard to tell, but it does look like it is still strictly increasing.
01:53
So this is a non -decreasing sequence.
01:56
And for this non -decreasing sequence to converge, it has to be bounded from above.
02:03
So we can try to find the limit using our cast calculator.
02:09
So let's plug in the expression.
02:14
Expression.
02:28
In n, we want to evaluate the limit as it goes to infinity.
02:32
We can see that it converges to a nice square root of e.
02:37
This is the decimal form if you don't need it.
02:40
So, we know that our upper limit is square root of e.
02:45
That is our, and so the sequence does converge.
02:49
And so now we have to do some limit analysis.
02:54
Sorry, go over this.
02:58
So we need to find integer n big n such that absolute value of a n minus l so this is the distance of the sequence to the limit the distance between those two and we want to find that this distance is less than a nicer sign less than or equal to 0 .01 4 n is greater than or equal to big so what this is saying is if we have our sequence goes along like this and we have our limit.
03:46
Let me use some different colors here.
03:49
So this is our sequence...