00:01
In this question we have a series summation n is equal to 2 to infinity 1 upon log n.
00:11
We are required to find whether this series converges or diverges by using the limit comparison test.
00:18
So let's see how to solve this question.
00:21
Consider, a .n is equal to 1 upon log n.
00:31
So we can write bn is equal to 1 upon n.
00:36
So from here we can write 4 all n greater than equals to 2 summation a and summation bn have positive values.
01:02
Therefore the series summation bn is equal to summation n is equal to summation n is equals to 1 to infinity 1 upon n is in the form summation n is equal to 1 to infinity 1 upon n to the power p and as p is equal to 1 which is less than equals to 1 then then by the p series test we can say that the series summation bn is divergent.
01:57
Now consider the limit limit n tends to infinity a .n upon bn.
02:09
So this will be equal to limit n tends to infinity n upon log n.
02:17
Now differentiate the numerator and denominator separately so we will have limit n tends to infinity 1 upon 1 upon n.
02:29
Now substitute infinity on the place of n and further calculate so we get limit n tends to infinity a n upon b n is equal to infinity.
02:40
And now let's discuss the limit comparison test and the test is shown below...