Question 1: Let x1(n) = {1, 2, 2, 1}. A new sequence x2 (n) is formed using: (x₁(n) 0≤ n ≤3 x2(n) = x(n4) 4≤ n ≤7 otherwise a) Express X2(ejw) in terms of X₁(ejw)without explicitly computing X₁ (ejw). b) Verify your result using MATLAB by computing and plotting magnitudes of the respective DTFTs.