Fourier Series and Transform: Difference between revisions

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==Intuition==
==Intuition==
Many physical systems can be modeled by square waves. Consider systems with on-off behavior, similar to an on-and-off switch. A sine wave and square wave looks like this respectively:<br>
Many physical systems can be modeled by square waves. Consider systems with on-off behavior, similar to an on-and-off switch. A sine wave and square wave looks like this respectively:<br>
[[File:sinewave.png|400px|]][[File:Arrow.png|200px|]][[File:squarewave.png|300px|]]
[[File:sinewave.png|400px|]][[File:Arrow.png|200px|]][[File:squarewave.png|300px|]]<br>
As the diagram hints, we can use the Fourier Series to get from the sine wave to the square wave.

Revision as of 00:10, 6 December 2022

A Fourier series is an expansion of trigonometric functions to model periodic functions. This method proves useful in the study of harmonic systems as the analysis in a more familiar domain is much simpler than in its original domain. It has a variety of applications ranging from signal processing to quantum mechanics. The Fourier Series is defined as:
[math]\displaystyle{ f(x)=\sum_{n=1}^{\infty}{a_n\cos{(\frac{nx}{L}})}+\sum_{n=1}^{\infty}{b_n\sin{(\frac{nx}{L}})} }[/math]

Intuition

Many physical systems can be modeled by square waves. Consider systems with on-off behavior, similar to an on-and-off switch. A sine wave and square wave looks like this respectively:

As the diagram hints, we can use the Fourier Series to get from the sine wave to the square wave.