Fourier Series Coefficients - How to Calculate and Integrate for Even Functions

In summary, the conversation revolves around calculating Fourier series coefficients using the usual equations and determining the appropriate limits and function values. The conversation also mentions using shortcuts for even functions.
  • #1
Studious_stud
39
0

Homework Statement



ynms7.jpg


Homework Equations



Usual equations for calculating Fourier series coefficients

The Attempt at a Solution



Well essentially I don't know what to let f(x) equal to for calculating the coefficients a0, an and bn. Should I use 1 + x/pi or 1 - x/pi? And what about the limits? I was thinking maybe between -pi and pi.

Anyway here's my progress thus far, I think the graph is ok anyways.

519dnb.jpg


Thanks dudes. I would use latex but I suck at it
 
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  • #2
Looks fine.
Just start with the generic formula for a0.
The integral can be calculated by splitting it into the sum of 2 integrals.
 
  • #3
Take for example:

[tex]a_1=\frac{1}{\pi}\int_{-\pi}^{\pi} f(x)\cos(x)dx[/tex]

now, I want to integrate that function between -pi and pi but it's defined differently in two intervals. Why not just split up the intervals and write:

[tex]a_1=\frac{1}{\pi}\left(\int_{-\pi}^{0} (1+x\pi)\cos(x)dx+\int_{0}^{\pi} (1-x\pi)\cos(x)dx\right)[/tex]

However it is an even function so there are short-cuts for computing them. But for now, you may want to just do it this way.
 
  • #4
jackmell said:
Take for example:

[tex]a_1=\frac{1}{\pi}\int_{-\pi}^{\pi} f(x)\cos(x)dx[/tex]

now, I want to integrate that function between -pi and pi but it's defined differently in two intervals. Why not just split up the intervals and write:

[tex]a_1=\frac{1}{\pi}\left(\int_{-\pi}^{0} (1+x\pi)\cos(x)dx+\int_{0}^{\pi} (1-x\pi)\cos(x)dx\right)[/tex]

However it is an even function so there are short-cuts for computing them. But for now, you may want to just do it this way.

I like Serena said:
Looks fine.
Just start with the generic formula for a0.
The integral can be calculated by splitting it into the sum of 2 integrals.

Great I understand completely now, thanks everyone. :smile:
 

FAQ: Fourier Series Coefficients - How to Calculate and Integrate for Even Functions

What is a Short Fourier series?

A Short Fourier series is a mathematical representation of a periodic function using a finite number of sine and cosine waves. It is a simplified version of the Fourier series, which is an infinite series.

How is a Short Fourier series calculated?

A Short Fourier series is calculated by finding the coefficients of the sine and cosine waves that best fit the periodic function. This can be done using various methods such as the Discrete Fourier Transform or the Fast Fourier Transform algorithm.

What is the significance of a Short Fourier series?

A Short Fourier series is significant because it allows us to approximate complex periodic functions using a smaller number of components. This makes it easier to analyze and manipulate these functions, making it a useful tool in various fields such as signal processing, image processing, and data compression.

Can a Short Fourier series represent any type of periodic function?

No, a Short Fourier series can only represent periodic functions that meet certain conditions, such as being continuous and having a finite number of discontinuities. If these conditions are not met, the series may not accurately represent the function.

How is a Short Fourier series different from a Fourier transform?

A Short Fourier series is a finite series that represents a periodic function, while a Fourier transform is an infinite series that represents a non-periodic function. Additionally, a Short Fourier series uses only sine and cosine waves, while a Fourier transform uses complex exponential functions.

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