Geometric Series Test Rather Than Integral Test

Click For Summary

Homework Help Overview

The discussion revolves around the convergence of the series \(\sum_{n=1}^{\infty} \frac{1}{2^n}\) and the application of the geometric series test. Participants are exploring whether the series can be manipulated to fit the criteria for this test.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Some participants suggest that the series can be expressed in the form of a geometric series, while others question the necessity of manipulation. There is also a discussion regarding the starting index of the series and its implications for applying the geometric series test.

Discussion Status

Participants are actively engaging with the problem, raising questions about the validity of certain assumptions regarding the series' starting index. Some guidance has been offered regarding how to adjust the series to fit the geometric series framework, but there is no explicit consensus on the correct approach.

Contextual Notes

There is mention of a potential misunderstanding regarding the starting index of the series, with references to teacher guidance that may need clarification. The implications of starting the series at \(n=1\) versus \(n=0\) are under consideration.

Bashyboy
Messages
1,419
Reaction score
5

Homework Statement


\sum_{n=1}^{\infty} \frac{1}{2^n}


Homework Equations





The Attempt at a Solution


Could I some how manipulate this to fit a geometric series, so that I may instead use the geometric series test?
 
Physics news on Phys.org
\frac{1}{2^n}= \left(\frac{1}{2}\right)^n
 
Bashyboy said:

Homework Statement


\sum_{n=1}^{\infty} \frac{1}{2^n}

Homework Equations



The Attempt at a Solution


Could I some how manipulate this to fit a geometric series, so that I may instead use the geometric series test?

Hint:

No manipulation is required.
 
Well, I was told by my teacher that n couldn't equal one for the geometric series to be implemented, was he, perhaps, wrong?
 
Bashyboy said:
Well, I was told by my teacher that n couldn't equal one for the geometric series to be implemented, was he, perhaps, wrong?
Do you mean, n can't start at 1, it must start at zero?

If so factor 1/2 out of your series & change the index accordingly,

else,

Add 1 to your series so that it starts at n=0, and subtract 1 from your result.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K