I Hope this might help u to read better,

assess the series

infinity

sum of ((-2)^n)/(3n+1)!

n = 0

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- Jun 22nd 2006, 10:29 AMdistancen =0
I Hope this might help u to read better,

assess the series

infinity

sum of ((-2)^n)/(3n+1)!

n = 0 - Jun 22nd 2006, 01:11 PMCaptainBlack
Don't post the same question multipe times

RonL - Jun 22nd 2006, 05:09 PMdistance
Sorry about that. Anyone can do this problem ( bouncing ball), the final is in next week, so i need to understand the problem

- Jun 22nd 2006, 05:41 PMJameson
Is your second thread titled "More series problems" something you would like deleted?

- Jun 22nd 2006, 06:23 PMThePerfectHacker

Use the generalized ratio test,

Note that,

Thus,

as

Which is less than 1 thus the series converges.

---

Also, the sequence,

Fits the conditions for Leibniz's alternating series test, thus it absolutely convergent. - Jun 23rd 2006, 03:50 AMJameson

Just analytically thinking about this, I can see that the factorial will very strongly outgrow the exponential as x gets larger. But more formally...

Thus this diverges.

Another way is to just take the limit of the original series.

If this limit is anything but zero, the series diverges. If it is zero, you must use another test to help you. - Jun 23rd 2006, 06:01 AMdistancesorry !
- Jun 23rd 2006, 08:34 AMJameson
ThePerfectHacker showed you how to show this converges. What's the problem? Don't worry about the lower bound of one versus zero. His work is still correct.

- Jun 23rd 2006, 08:44 AMdistancethanks a lotQuote:

Originally Posted by**Jameson**

- Jun 23rd 2006, 09:01 AMJameson

Always start by taking the limit of the series. If it's non-zero then the series diverges.

Thus this diverges. - Jun 23rd 2006, 09:06 AMThePerfectHackerQuote:

Originally Posted by**Jameson**

This is my 15:):)th Post!!! - Jun 23rd 2006, 11:10 AMJameson
What about this series then... :D :D

If the limit is one, this most certainly diverges. - Jun 23rd 2006, 12:05 PMThePerfectHacker
I do not understand you?

The ratio test is inconlusive for .

In your other post you said for ,

I was making a correction. - Jun 23rd 2006, 01:28 PMJameson
Oh! Ok. I was talking about the nth term test. If the nth term does not approach 0, then the series diverges. Yes you are correct about the Ratio Test.