Question

3.16 How many (non-isomorphic) graphs have the degree sequence s: 6, 6, 6, 6, 6, 6,6, 6, 6? 3.17 Consider the (unlabeled) graphs H1, H2, H3 and G of Figure 3.18. subgraph of G? (a) Is H1 isomorphic to a (b) Is H2 isomorphic to a subgraph of G? (c) Is H3 isomorphic to a subgraph of G? DEX H3: H2 H1 G: To lqr Figure 3.18: Graphs in Exercise 3.17 3.18 Does there exist a graph with exactly three components, exactly two of which are not isomorphic?

Answer 1

M a 3.17 d a)H n somoorphie to a-d-b-f- Swbanabh of nn bipas) hte,dhns canhains no odd odd eycle. So, H2 in not C Cycle and an e) H in inomaophie to 0 Sanb graph of ON 8,18, Suppose Contaim exact 3 com K3, and let onh ki K.Then ondi tiomahy , k3, K3K2hen Ki,Whieh s Hence dhere exist no such Gratbh pnents k,kek contradittion