Chapter 7: Q5P (page 377)

Use Parseval’s theorem and the results of the indicated problems to find the sum of the series in Probllems 5 to 9. The series $1 + \frac{1}{3^{2}} + \frac{1}{5^{2}} + \dots,$ using problem 9.6.

Short Answer

Expert verified

By Parseval theorem $\frac{π^{2}}{8} = \sum_{n = o d d}^{\infty} \frac{1}{n^{2}}$

Step by step solution

Given Information.

The given series is $1 + \frac{1}{3^{2}} + \frac{1}{5^{2}} + \dots$ .The sum of the series is to be found out.

Definition of Parseval’s theorem& average value

Parseval’s theorem is a theorem stating that the energy of a signal can be expressed as its frequency components’ average energy.

The average value of the square of the function over the interval is 1

Sum of the series

It is know that the solution of the problem 9.6 is $f (x) = \frac{4}{π} \sum_{n = o d d}^{\infty} \frac{s i n (\frac{π n x}{l})}{n}$

Use the Parseval theorem and the fact that the average value of the square of the function over the interval is 1

Now, $< {|f (x)|}^{2} > = 1 = \sum_{n = o d d}^{\infty} \frac{1}{2} {(\frac{4}{π n})}^{2} \Rightarrow \frac{π^{2}}{8} = \sum_{n = o d d}^{\infty} \frac{1}{n^{2}}$

Thus $\frac{π^{2}}{8} = \sum_{n = o d d}^{\infty} \frac{1}{n^{2}}$

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Use Parseval’s theorem and the results of the indicated problems to find the sum of the series in Probllems 5 to 9. The series $1 + \frac{1}{3^{2}} + \frac{1}{5^{2}} + \dots,$ using problem 9.6.

Short Answer

Step by step solution

Given Information.

Definition of Parseval’s theorem& average value

Sum of the series

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Most popular questions from this chapter

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Use Parseval’s theorem and the results of the indicated problems to find the sum of the series in Probllems 5 to 9. The series 1+132+152+⋯, using problem 9.6.

Short Answer

Step by step solution

Given Information.

Definition of Parseval’s theorem& average value

Sum of the series

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Famous Physicists

Scientific Method Physics

Physical Quantities And Units

Electricity and Magnetism

Classical Mechanics

Atoms and Radioactivity

Study anywhere. Anytime. Across all devices.

Use Parseval’s theorem and the results of the indicated problems to find the sum of the series in Probllems 5 to 9. The series $1 + \frac{1}{3^{2}} + \frac{1}{5^{2}} + \dots,$ using problem 9.6.