## Todai Entrance Exam: Subject 2019 – Problem 5

This is Kronecker delta. The equation can be interpreted as: If there exists a that then we return , otherwise we return . (1) According the given formula at the end of the problem: Reference: StackExchange (2) Reference: https://class.ece.uw.edu/235dl/EE235/Project/lesson19/lesson19.html (3) By Modulation Property of the Fourier Transform, we have: [...]