Find Fourier Transform of S_ε(x) for Laplace's Equation

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SUMMARY

The discussion focuses on finding the Fourier Transform of the function S_ε(x) = sgn(x)exp(ε|x|) for Laplace's equation in the half-plane, where ε > 0. The boundary condition involves the sign function, sgn(x), which is defined piecewise. Participants emphasize that S_ε(x) is an odd function, leading to the conclusion that the Fourier Transform will yield a Fourier sine series. Clarifications regarding the definition of sgn(x) are also noted, particularly addressing a typographical error in its representation.

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catcherintherye
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I am solving laplaces equation in the half plane and I have the following boundary condition of which I need to find the Fourier transform in the x-direction

[tex]S_\epsilon(x) = sgn(x)exp(\epsilon|x|), \epsilon >0[/tex]

[tex]sgn(x)=\left\{\begin{array}{cc}1,&\mbox{ if }<br /> x<0\\-1, & \mbox{ if } x<0\\ 0, &\mbox{ if } x=0\end{array}\right.[/tex]

any hints on how to approach this FT??
 
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there is a typo for the function sgn(x)? note that
[tex]-S_\epsilon (x) = S_\epsilon (-x)[/tex] is an odd function... and you should get a Fourier sine series
 

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