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<center><math>X(s) = \int_{-\infty}^{\infty} x(t)e^{-st} dt\!</math></center>
 
<center><math>X(s) = \int_{-\infty}^{\infty} x(t)e^{-st} dt\!</math></center>
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Let's consider the case where <math>s = j\omega\!</math>.
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<math>X(s)|_s=j\omega = X(j\omega)\!</math>

Revision as of 16:13, 24 November 2008

The Laplace Transform

The Laplace Transform is a generalization of the Fourier Transform. Instead of considering only the imaginary axis, $ j\omega\! $, (as the Fourier Transform does) the Laplace Transform considers all complex values represented by the general complex variable $ s\! $. Take the following simple picture:

Fourier Transform: $ x(t) --> X(\omega)\! $ where $ \omega\! $ is a frequency.

Laplace Transform: $ x(t) --> X(s)\! $ where $ s\! $ is a complex variable.

Mathematically, the Laplace Transform is represented as follows:

$ X(s) = \int_{-\infty}^{\infty} x(t)e^{-st} dt\! $

Let's consider the case where $ s = j\omega\! $.

$ X(s)|_s=j\omega = X(j\omega)\! $

Alumni Liaison

Recent Math PhD now doing a post-doctorate at UC Riverside.

Kuei-Nuan Lin