Absolute convergence of series

In summary, the conversation is about someone seeking feedback on whether their reasoning for examining the absolute convergence of a given series is correct. They mention using the limit comparison test and conclude that the series diverges based on the fact that another series it is being compared to also diverges. A forum moderator suggests using LaTeX for writing equations instead of attaching images.
  • #1
Kqwert
160
3

Homework Statement


Hello, I need some feedback on whether this reasons is correct.

consider the series
gif.gif


Examine the series for absolute convergence.

Homework Equations

The Attempt at a Solution


How I have solved this, using the limit comparison test:

we have:

gif.gif


introducing

gif.gif


we have that
gif.gif


We know that bn diverges (harmonic series) , and we can therefore conclude that also an diverges. True?
 

Attachments

  • gif.gif
    gif.gif
    907 bytes · Views: 509
  • gif.gif
    gif.gif
    554 bytes · Views: 330
  • gif.gif
    gif.gif
    301 bytes · Views: 328
  • gif.gif
    gif.gif
    585 bytes · Views: 329
Physics news on Phys.org
  • #2
Yes. That is correct.
 
  • #3
@Kqwert, instead of posting a bunch of image attachments, why don't you take 5 minutes and look at our LaTeX tutorial (https://www.physicsforums.com/help/latexhelp/)?
The first summation in your post is ##\sum_{n = 1}^\infty \frac{(-1)^{n + 1}}{n + \ln(n)}##

The MathJax markup I used above is ##\sum_{n = 1}^\infty \frac{(-1)^{n + 1}{n + \ln(n)}##
 
  • Like
Likes Kqwert

What is absolute convergence of series?

Absolute convergence of series is a mathematical concept that refers to the convergence of a series where the terms are positive, regardless of the order in which they are added. It means that the series will converge to a finite value, regardless of how the terms are arranged.

How is absolute convergence different from conditional convergence?

Conditional convergence refers to the convergence of a series where the terms are both positive and negative, and the series only converges if the terms are arranged in a specific order. Absolute convergence, on the other hand, guarantees convergence regardless of the order of the terms.

What is the significance of absolute convergence in mathematics?

Absolute convergence is important in mathematics because it allows us to manipulate series and perform operations on them without worrying about the order of the terms. It also guarantees that the series will converge to a finite value, which makes it easier to analyze and apply in various mathematical problems.

How can I determine if a series is absolutely convergent?

To determine if a series is absolutely convergent, you can use the ratio test or the comparison test. The ratio test compares the ratio of consecutive terms in a series to a limiting value, while the comparison test compares the series in question to a known series with known convergence properties.

What are some real-life applications of absolute convergence of series?

Absolute convergence of series has various applications in fields such as physics, engineering, and finance. It is used in the analysis of alternating current circuits, in the study of oscillating systems, and in calculating the stability of structures. In finance, it is used to analyze the stability of financial markets and to model investment strategies.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
187
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Calculus and Beyond Homework Help
Replies
7
Views
958
  • Calculus and Beyond Homework Help
Replies
8
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
258
  • Calculus and Beyond Homework Help
Replies
2
Views
737
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
29
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
711
  • Calculus and Beyond Homework Help
Replies
14
Views
1K
Back
Top