Help with Fourier transform of T'(x)/x

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SUMMARY

The discussion focuses on finding the Fourier transform of the expression \(\frac{1}{x}\frac{\partial T}{\partial x}\). The user proposes using convolution to separate the Fourier transform into the product of the transforms of \(\frac{1}{x}\) and \(\frac{\partial T}{\partial x}\). The context involves solving the partial differential equation \(\frac{\partial^{2}T}{\partial x^{2}} + \frac{1}{x}\frac{\partial T}{\partial x} = \frac{1}{\alpha}\frac{\partial T}{\partial t}\) with specified initial and boundary conditions, indicating a need for advanced mathematical techniques.

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  • Understanding of Fourier transforms and their properties
  • Familiarity with convolution in the context of Fourier analysis
  • Knowledge of partial differential equations (PDEs)
  • Experience with boundary and initial value problems
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  • Study the properties of Fourier transforms, particularly for singular functions like \(\frac{1}{x}\)
  • Learn about convolution theorems in Fourier analysis
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  • Investigate the implications of boundary conditions on Fourier solutions
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Mathematicians, physicists, and engineering students involved in solving partial differential equations, particularly those utilizing Fourier analysis techniques.

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Homework Statement



[tex]T(x,t)[/tex]

What is the Fourier transform of
[tex] \frac{1}{x}\frac{\partial T}{\partial x}[/tex]

[tex] F(\frac{1}{x}\frac{\partial T}{\partial x}) = \int^{\infty}_{-\infty} \frac{1}{x}\frac{\partial T}{\partial x} e^{i \theta x}dx = ??[/tex]

Homework Equations


The Attempt at a Solution



Can this be split up using convolution into...

[tex]F(\frac{1}{x}\frac{\partial T}{\partial x}) = F(\frac{1}{x})F(\frac{\partial T}{\partial x}) =\int^{\infty}_{-\infty} \frac{1}{x} e^{i \theta x}dx \int^{\infty}_{-\infty} \frac{\partial T}{\partial x} e^{i \theta x}dx[/tex]
 
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You will need to prove that the convolution of 1/x and dT/dx is (1/x)(dT/dx).
 
Okay thanks. I was trying to solve
[tex] \frac{\partial^{2}T}{\partial x^{2}} + \frac{1}{x}\frac{\partial T}{\partial x} = \frac{1}{\alpha}\frac{\partial T}{\partial t}<br /> [/tex]

for [tex] 0 < x < \infty [/tex] and initial condition like [tex] T(x,0) = g(x) [/tex]
with boundary conditions [tex] T(\infty,t) = C_{1} [/tex] and [tex] T(0,t) = f(t)[/tex]

I got stuck with separation of variables and method of characteristics so I was going to try Fourier method
 

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