Question

WN^k+N/2=?

(a) WN^k

(b) -WN^k

(c) WN^-k

(d) None of the mentioned

The question was asked in semester exam.

I'd like to ask this question from Efficient Computation of DFT FFT Algorithms topic in division DFT Efficient Computation – Fast Fourier Transform Algorithms of Digital Signal Processing

Answer 1

The correct answer is (b) -WN^k

For explanation: According to the symmetry property, we get WNk+N/2=-WN^k.