Fourier Integrals and Division

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SUMMARY

The discussion focuses on finding the Fourier transforms of the functions f(x) = cos(x) and g(x) = sin(x) over the interval from -π/2 to π/2. The Fourier transform f(ω) is calculated as f(ω) = ∫f(x)e^(-iωx) dx, resulting in f(ω) = π[δ(ω - 1) + δ(ω + 1)]. Similarly, g(ω) yields g(ω) = π[δ(ω - 1) - δ(ω + 1)]. The division f(ω)/g(ω) results in -1/(iω), which is confirmed by multiple students, leading to a discussion on the underlying identities of Fourier integrals.

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  • Understanding of Fourier transforms and their properties
  • Familiarity with Dirac delta functions
  • Knowledge of complex exponentials and integration techniques
  • Basic concepts of linear operators in functional analysis
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  • Study the properties of Dirac delta functions in Fourier analysis
  • Learn about linear operators and their applications in transforming functions
  • Explore the relationship between sine and cosine functions in Fourier transforms
  • Investigate common identities and theorems related to Fourier integrals
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Yosty22
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Homework Statement



(a) Find the Fourier transform f(ω) of: f(x) = cos(x) between -pi/2 and pi/2
(b) Find the Fourier transform g(ω) of: g(x) = sin(x) between = -pi/2 and pi/2
(c) Without doing any integration, determine f(ω)/g(ω) and explain why it is so

Homework Equations



f(ω) = ∫f(x)e-iωx dx

The Attempt at a Solution



I was able to do parts (a) and (b) and verified my answers, however part (c) is giving me some problems. The division is straightforward for the two transformed equations. When I do the division, I get f(ω)/g(ω) = -1/(iω). I have verified this with fellow students as well, and we have all gotten the same thing. I am just confused as to the why . I feel like it might be some identity of Fourier integrals, but I cannot find it. I have looked through my textbook and I have been looking online, but I cannot really understand exactly why I get the answer I do.

Any help would be greatly appreciated.
 
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Hint: What linear operator can you apply to g(x) to get f(x)?
 
Even easier: What linear operator can you use to come from f(x) to g(x):biggrin:.
 

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