Let A be the adjacency matrix of a digraph. What do you know about the digraph in each of the following cases? (a) The third row of A is all zeros. (b) The fourth column of A is all zeros. ( c) The sum of the elements in the fifth row of A is 3. ( d) The sum of the elements in the second column of A is 2. (e) The second row of A 3 is all zeros. (f) The third column of A 4 is all zeros.

ISLAMICWORLD Basics Al-Khwarizimi o o o o o o o ▯▯ + ▯▯ + ▯ = 0 2 o ▯ + ▯▯ = ▯ 2 ▯(▯ 2) + ▯ − (▯ 2) ▯ + 6▯ = 4 (▯ + 3)2= 4 + 9 (▯ + 3) = 13 ▯ + 3 = √13 ▯ = √ 13 − 3 ▯ ▯ + 16▯ = 25 (▯ + 8)2= 25 + 16(4) 2 (▯ + 8) = 89 ▯ + 8 = √89 ▯ = √ 89 − 8 10/12/2016 ISLAMICWORLD Basics Knowledge was important to them. What they were learning was tremendous compared to ot