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# Parseval's theorem. watch

1. The question: Use Parseval's Theorem to show that

I thought I had completed the question but obviously not. How do I get it into the required form?

EDIT: forgot to mention the function.

if and if
2. What is your definition of Fourier transform, and what is your version of Parseval's theorem?
3. (Original post by DFranklin)
What is your definition of Fourier transform, and what is your version of Parseval's theorem?
Fourier transform:

Parsevals' Identity:

We were a given a different parseval's identity but the one given above was used for a worked example that is similar to this one. But in our worked one, we ended it where I did so I don't know how to continue it further.
4. Are you sure what you've written for Parseval's Identity is what you meant?
5. (Original post by DFranklin)
Are you sure what you've written for Parseval's Identity is what you meant?
The original one involved the complex conjugate of and on the other side. But we did an example in lectures and we used the one that I posted previously so I thought it'd be relevant to use that one for this question too as there was only a different variable involved and most of the question was directly similar. Have I missed the point somewhere?
6. The one with on the LHS is the useful one here.
7. Ok, I just realised I missed out important information when I typed this out the first time. I am revisiting the question now and I think I have the answer but I just want to check. I feel a bit iffy as it didn't really involve any calculations.

Fourier transform of f(x):

. 0, otherwise.

Fourier tranform of h(x) is :

I have literally just multiplied the f(x) and h(x) and then their corresponding transforms together and equated them with the appropriate limits and let my epsilon = 1 and I have shown what is asked to be shown. I just want to make sure if I did it the correct way. Can I just let epsilon = 1 like that?

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