How can the sum of 1/n² be used to solve for the sum of 1/(2n-1)²?

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In summary: You can do it! In summary, the conversation discusses how to use the fact that ∑(n=1) to (n=∞) of 1/n² = π²/6 to show that ∑(n=1) to (n=∞) of 1/(2n-1)² = π²/8. The approach suggested is to manipulate the series ∑1/(2n)² in order to arrive at the desired result.
  • #1
bcucinel
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Homework Statement



It can be shown that ∑(n=1) to (n=∞) of 1/n² = π²/6

use this fact to show that ∑(n=1) to (n=∞) of 1/(2n-1)² = π²/8

Homework Equations





The Attempt at a Solution

 
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  • #2
bcucinel said:

Homework Statement



It can be shown that ∑(n=1) to (n=∞) of 1/n² = π²/6

use this fact to show that ∑(n=1) to (n=∞) of 1/(2n-1)² = π²/8

Homework Equations





The Attempt at a Solution

What have you tried? You need to make an attempt at a solution before anyone can give you any help.
 
  • #3
Hint: It is so easy, you can do it in your head in less than ten seconds.
 
  • #4
My attempt which needs to be shown on paper...

First I wrote out the first few terms of ∑(n=1) to (n=∞) of 1/n². So 1+1/4+1/9+1/16+...+1/n² = π²/6.

I then just tried to simply substituted (2n-1) into the previous summation in place of just n to somehow show that ∑(n=1) to (n=∞) of 1/(2n-1)² = π²/8... but I have no idea how to accurately demonstrate the rest of the proof.
Any additional help would be appreciated.
 
  • #5
What are the first few terms of
[tex]\sum_{n = 1}^{\infty}\frac{1}{(2n - 1)^2}[/tex]? How does this series relate to the other series?
 
  • #6
When writing out the first few terms of Σ1/(2n-1)², I noticed that this represents the terms when n is some odd number from the first summation, ∑1/n², but I'm stuck as to the proof with setting that equal to 8.
 
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  • #7
Show me the first five terms of Σ1/(2n-1)².
Show me the first five terms of Σ1/n².

Pretend for the time being that you don't what the answer is supposed to be. It seems to me that you are too focused on the pi^2/8 result, and not focused enough on how to get there.
 
  • #8
Σ1/(2n-1)²: 1+1/9+1/25+1/49+1/81+...

Σ1/n²: 1+1/4+1/9+1/16+1/25+...
 
  • #9
And which terms are missing from the first series that are in the second series? What is Σ1/n² - Σ1/(2n-1)² ?
 
  • #10
1/4+1/16+1/36+...

Σ1/n² - Σ1/(2n-1)² then equals Σ1/(2n)² from n=1 to infinity
 
  • #11
bcucinel said:
1/4+1/16+1/36+...

Σ1/n² - Σ1/(2n-1)² then equals Σ1/(2n)² from n=1 to infinity
Now, can you manipulate this series--Σ1/(2n)²--to get to something you know?
 
  • #12
Thank you, I understand all of that perfectly... The issue I am having with the problem, however, is that I don't recall ever being taught in my calculus class exactly how to determine the Sn of a series like Σ1/(2n)²... If there is some technique that I could use please let me know.
 
  • #13
bcucinel said:
Thank you, I understand all of that perfectly... The issue I am having with the problem, however, is that I don't recall ever being taught in my calculus class exactly how to determine the Sn of a series like Σ1/(2n)²... If there is some technique that I could use please let me know.

Just simplify 1/(2n)²
 
  • #14
How exactly?
 
  • #15
Write 1/(2n)² in a different way. C'mon, this ain't rocket science...
 

FAQ: How can the sum of 1/n² be used to solve for the sum of 1/(2n-1)²?

How do you calculate a summation?

To calculate a summation, you need to add up a series of numbers. The formula for calculating a summation is ∑x = x1 + x2 + x3 + ... + xn, where x represents the numbers in the series and n represents the total number of terms.

What is the purpose of calculating a summation?

Calculating a summation is used to find the total of a series of numbers. It is commonly used in mathematics and science to analyze data and make predictions based on patterns in the data.

What are some common notations used for summations?

The most common notation used for summations is the sigma notation, which is represented by the Greek letter ∑. Other notations include the capital letter S and the word "sum" written above the series of numbers.

What are some strategies for simplifying a summation?

There are a few strategies that can be used to simplify a summation, including factoring out common terms, using algebraic properties, and breaking the summation into smaller parts. It is also helpful to have a thorough understanding of basic arithmetic and algebra.

How is a summation related to integrals and derivatives?

A summation is closely related to integrals and derivatives, as all three concepts involve finding the total or change of a function. In fact, integrals and derivatives can be used to evaluate certain types of summations, particularly those involving continuous functions.

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