Integration of complex exponentials

[Fedya]

Where does impulse function come from? I don’t know where to start, Euler?

(see attachment)

The book simply gives it without any explanation or derivation. Maybe the derivation is too complex for me, but I’m willing to look into it, even if it breaks my head!

Thanks in advance!

 

[hamster143]

Look at this backwards. What is the Fourier transform of the impulse function?

 

[Fedya]

Look at this backwards. What is the Fourier transform of the impulse function?

Thank you for the post!

The book uses your solution (B.P. Lathi). I was just hopping for more formal one. Is there one?

Thanks
-Fedya