2.1 A discrete-time signal x(n) is defined as 1 x(n) = 1, 0, -3≤ n ≤ -1 0 ≤ n ≤ 3 elsewhere (a) Determine its values and sketch the signal x(n). (b) Sketch the signals that result if we: 1. First fold x(n) and then delay the resulting signal by four samples. 2. First delay x(n) by four samples and then fold the resulting signal. (c) Sketch the signal x(−n +4). (d) Compare the results in parts (b) and (c) and derive a rule for obtaining the signal x(-n + k) from x(n). (e) Can you express the signal x(n) in terms of signals 8(n) and u(n)?