Let x be a fixed positive integer. Is it possible to have a
graph G with...
Let x be a fixed positive integer. Is it possible to have a
graph G with 4x + 1 vertices such that G has a vertex of degree d
for all d = 1, 2, ..., 4x + 1? Justify your answer. (Note: The
graph G does not need to be simple.)
Let G be an abelian group and n a fixed positive integer. Prove
that the following sets are subgroups of G.
(a) P(G, n) = {gn | g ∈ G}.
(b) T(G, n) = {g ∈ G | gn = 1}.
(c) Compute P(G, 2) and T(G, 2) if G = C8 ×
C2.
(d) Prove that T(G, 2) is not a subgroup of G = Dn
for n ≥ 3 (i.e the statement above is false when G is...
Let k be an integer satisfying k ≥ 2. Let G be a connected graph
with no cycles and k vertices. Prove that G has at least 2 vertices
of degree equal to 1.
If G = (V, E) is a graph and x ∈ V , let G \ x be the graph
whose vertex set is V \ {x} and whose edges are those edges of G
that don’t contain x.
Show that every connected finite graph G = (V, E) with at least
two vertices has at least two vertices x1, x2 ∈ V such that G \ xi
is connected.
7. Let m be a fixed positive integer.
(a) Prove that no two among the integers 0, 1, 2, . . . , m − 1
are congruent to each other modulo m.
(b) Prove that every integer is congruent modulo m to one of 0,
1, 2, . . . , m − 1.
Determine, for a given graph G =V,E and a positive integer m ≤
|V |, whether G contains a clique of size m or more. (A clique of
size k in a graph is its complete subgraph of k vertices.)
Determine, for a given graph G = V,E and a positive integer m ≤
|V |, whether there is a vertex cover of size m or less for G. (A
vertex cover of size k for a graph G =...
CLIQUE
INPUT: Graph G, positive integer l
PROPERTY: G has a set of l manually adjacent nodes.
CLIQUE COVER
INPUT: graph G’, positive integer k
PROPERTY: N’ is the union of k or fewer cliques.
So, Question is : Show that CLIQUE and CLIQUE COVER is cycle
base on the property that is given?
What does it mean no computer!!
Let a be a positive constant number. Draw the graph of a
catenary y=acosh(x/a). Calculate the arc length s from the point
(0,a) to the point (x,acosh(x/a)), and find the expression of the
curve in terms of the parameter s.
Let G be a group, and let a ∈ G be a fixed element. Define a
function Φ : G → G by Φ(x) = ax−1a−1.
Prove that Φ is an isomorphism is and only if the group G is
abelian.
6. Let t be a positive integer. Show that 1? + 2? + ⋯ + (? − 1)?
+ ?? is ?(??+1).
7. Arrange the functions ?10, 10?, ? log ? , (log ?)3, ?5 + ?3 +
?2, and ?! in a list so that each function is big-O of the next
function.
8. Give a big-O estimate for the function ?(?)=(?3
+?2log?)(log?+1)+(5log?+10)(?3 +1). For the function g in your
estimate f(n) is O(g(n)), use a simple function g...
Let G be a simple graph. G is said to be maximal planar if it
is planar and the addition of any new edge to G results in a
(simple) non-planar graph. Examples of maximal non-planar graphs
are K4 , K5 minus an edge, and K3,3 minus an edge.
(a) Show that a maximal planar graph is connected.
(b) Show that a maximal planar graph of order ≥3 has no
bridges.
(c) Show that every face of a maximal planar...