0 votes 0 votes For the sequence $x[n] = \{1, -1,1, -1\},$ with $n = 0,1,2,3,$ the DFT is computed as $X(k) = \displaystyle{}\Sigma^3_{n=0}x[n]e^{-j\frac {2\pi}{4}nk}$, for $k = 0,1,2,3.$ The value of k for which $X(k)$ is not zero is 0 1 2 3 Others gate2018-in + – gatecse asked Feb 20, 2018 • edited Mar 20, 2021 by Lakshman Bhaiya gatecse 1.4k points answer See all 0 reply