(a) Figure P8.21-1 shows two periodic sequences, with period N = 7. Find a sequence...

(a) Figure P8.21-1 shows two periodic sequences, with period N = 7. Find a sequence whose DFS is equal to the product of the DFS of and the DFS of i.e.,

(b) Figure P8.21-2 shows a periodic sequence with period N = 7. Find a sequence whose DFS is equal to the product of the DFS of and the DFS of i.e.,