What is the next step for determining convergence or divergence of this series?

whatlifeforme
Messages
218
Reaction score
0

Homework Statement


determine either absolute convergence, conditional convergence, or divergence for the series.

Homework Equations


\displaystyle \sum^{∞}_{n=1} (-1)^n \frac{6n^8 + 3}{3n^5 + 3}

The Attempt at a Solution


I cannot use the alternating series test since the function is increasing not decreasing.What should i do next?
 
Physics news on Phys.org
whatlifeforme said:

Homework Statement


determine either absolute convergence, conditional convergence, or divergence for the series.


Homework Equations


\displaystyle \sum^{∞}_{n=1} (-1)^n \frac{6n^8 + 3}{3n^5 + 3}


The Attempt at a Solution


I cannot use the alternating series test since the function is increasing not decreasing.What should i do next?
Since the sequence (apart from the (-1)n factor) is increasing, doesn't that give you a hint as to what the series is doing? It might help to write a few terms in the series.
 
can i use the divergence test?
 
Yep, it diverges since its terms do not approach zero.
 
HS-Scientist said:
Yep, it diverges since its terms do not approach zero.

thanks.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

Similar threads

Replies
3
Views
1K
Replies
4
Views
2K
Replies
1
Views
1K
Replies
4
Views
1K
Replies
2
Views
2K
Replies
5
Views
2K
Replies
1
Views
1K
Back
Top