(b) Suppose G is a simple connected graph with 12 vertices and 16 edges. Suppose 4 of its vertices are degree 1, and 3 of its vertices are degree 2. Prove that G is planar. (Hint: Kuratowski)
(c) Let G be any simple connected planar graph with n vertices and e edges. Suppose there are exactly y vertices of degree 2. Assume that n - y > 3. Prove that e < 3n - y - 6. (Hint: Explain why the degree-2 vertices can be erased, and how to take care of any resulting loops or multiple edges.)
(d) Suppose that a connected simple graph G' has exactly 10 vertices of degree 4, 8 vertices of degree 5, and all other vertices have degree 7. Find the maximum possible number of degree-7 vertices G could have, so that G would still be planar.
Step by stepSolved in 3 steps
- prove If G is a plane graph with n vertices, m edges and r regions, then n - m + r = 1 + k(G).arrow_forwardFor which of the following does there exist a simple graph G = - (V, E) satisfying the specified conditions? Select one: O A. It has 7 vertices, 10 edges, and more than two components. B. It has 8 vertices, 8 edges, and no cycles. O C. It has 6 vertices, 11 edges, and more than one component. O D. It is connected and has 10 edges, 5 vertices and fewer than 6 cycles. O E. It has 3 components, 20 vertices and 16 edges.arrow_forwardPreview Activity 11.1.1. In this activity we introduce the concept of a double Riemann sum. ………….. a. Review the concept of the Riemann sum from single-variable calculus. Then, explain how we define the definite integral ff(x) dz of a continuous function of a single variable z on an interval [a, b]. Include a sketch of a continuous function on an interval [a,b] with appropriate labeling in order to illustrate your definition. b. In our upcoming study of integral calculus for multivariable functions, we will first extend the idea of the single-variable definite integral to functions of two variables over rectangular domains. To do so, we will need to understand how to partition a rectangle into subrectangles. Let R be rectangular domain R = {(z,y): 0≤x≤6,2 ≤ y ≤ 4} (we can also represent this domain with the notation [0, 6] x [2, 4]), as pictured in Figure 11.1.1. 2 Figure 11.1.1. Rectangular domain R with subrectangles. To form a partition of the full rectangular region, R, we will…arrow_forward
- For each of the graphs :(i) Find all edges that are incident on y1.(ii) Find all vertices that are adjacent to y3.(iii) Find all edges that are adjacent to e1.(iv) Find all loops.(v) Find all parallel edges.(vi) Find all isolated vertices.(vii) Find the degree of y3.arrow_forwardTrue or False. Justify Your Answer. a) There is a vertex v in a bipartite graph G = (V,E) with deg (v) = m+n. Where m = |V1| and n = |V2| b) is it possible for a graph to be a tree and complete bipartite graph at the same time?arrow_forwardLet G be a graph of order n that is isomorphic to its complement G. How many edges does G have? Explain your answer. If a graph G has n vertices, all of which but one have odd degree, how many vertices of odd degree are there in G, the complement of G? Prove your answer.arrow_forward
- -nsider the following graph G(V, E) w • The set of vertices V: {2,3, 4, 6, 8, • The set of edges E: {(a, b) e Z² : « a) Draw the graph G. b) Draw the graph G3arrow_forwardLet G be a critical 2-connected graph; this means that G is 2-connected but no graph G - e for e e E(G) is 2-connected. (a) Prove that at least one vertex of G has degree 2. (b) For each n, find an example of a critical 2-connected graph with a vertex of degree at least n.arrow_forward
- Advanced Engineering MathematicsAdvanced MathISBN:9780470458365Author:Erwin KreyszigPublisher:Wiley, John & Sons, IncorporatedNumerical Methods for EngineersAdvanced MathISBN:9780073397924Author:Steven C. Chapra Dr., Raymond P. CanalePublisher:McGraw-Hill EducationIntroductory Mathematics for Engineering Applicat...Advanced MathISBN:9781118141809Author:Nathan KlingbeilPublisher:WILEY
- Mathematics For Machine TechnologyAdvanced MathISBN:9781337798310Author:Peterson, John.Publisher:Cengage Learning,