4. Use K-map to determine the minimum sum of products (SOP) and the minimum product of sums (POS) for the following functions: (a) f(w, x, y, z) = m(0,4,6,7,9, 11, 14, 15) (b) f(w, x, y, z) = 2m10, 4, 6, 7, 9, 11, 14, 15) + D01, 3, 10, 13)