Definition | ||||||
The Fourier Transform is merely a restatement of the Fourier Integral: . Using the complex form of Cosine, we can easily prove that the above integral can be re-written as: .
The above integral can be expressed by the following Fourier Transform pair: Since is a dummy variable, we can replace it with and define the Fourier transform of and its inverse transform as:
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where and are the Fourier and its inverse transform operators, respectively. |
Fourier Cosine and Sine Transforms | |
If is an even function, then its Fourier Integral is equivalent to the following pair of equations: | |
where is called the Fourier Cosine Transform operator. On the other hand, if is an odd function, then its Fourier Integral is equivalent to the following pair of equations: | |
where is called the Fourier Sine Transform operator. |