I have a question about my Mathematics Stack Exchange post: Prove the following relation (using Fourier analysis)
This is my first time on Mathematics Stack Exchange. I didn't think my question was vague, and I did try to solve it on my own for quite a long time before asking here. So I'm puzzled by the downvotes I've received. I don't know where I went wrong. Maybe I should have added a tag for Poisson-summation-formula? But then if I knew that I wouldn't need to ask the question in the first place. I would like to know what I did wrong so that I don't repeat the same mistake again. Thank you.