We know that Least Upper bound axiom means a ordered set S in wich for every nonempty subset A which is bounded above then supA i.e least upper bound of A exists in set S.
But Q not satisfy this axiom.
Because observe the following subset
A={x€Q /x²<2}
Then clearly A is nonempty bounded subset of Q
Because it is bounded by all elements x€Q and x²>2
Now we observe that SupA=√2= square root of 2
But we know that √2=square root of 2 does not belong to Q
Since it is one irrational number
So clearly supA does belong to Q
I. E Q has no least upper bound property
17 Give an example to show why the least upper bound axiom close not applay to...
Analysis Show that the least upper bound of any nonempty set of real numbers is unique
Prove this theorem.. Suppose S is a set of numbers, M is the least upper bound of S and M does not belong to S. Then, M is a cluster point of S.
(4) Suppose that an → a. Prove or disprove: (a) If an is an upper bound fora set S for all n, then a is also an upper bound for S. (b) If an € (0,1) for all n, then a € (0,1). (c) If an € [0,1] for all n, then a € [0, 1]. (d) If an is rational, then a is rational.
4. For the following sets determine the least upper bound (it is
not necessary
to prove that it is the least upper bound):
a.) M = [0; 1] [ (3; 4)
b.) M =
n5n + 1
4n ? 3
n 2 N
o
c.) M =
n n + 1
2n + 13
n 2 N
o
d.) M =
nXn
i=1
9
10i
n 2 N
o
e.) M =
n
xjx > 0 and x2 < 5g:...
Prove that the real numbers have the least upper bound property, i.e. any bounded above subset S ⊆ R has a supremum if and only if the real numbers have the greatest lower bound property, i.e. any bounded below subset T ⊆ R has an infimum.
Question 2. Prove that if S C R is bounded above then its least upper bound is unique. Le, that if X,, R are both least upper bounds for S then ג ,
6. Let X be a non-empty subset of an ordered field with the least upper bound property. Supposed that X is bounded above and define -X = {-1 : TEX} Prove that supX = - inf(-X).
QUESTION 7 Consider the poset (A, R) represented by the following Hasse diagram (2 (a) Give each of the following If any do not exıst, explan why (i) The greatest element of (A, R) (i:) The least element of (A, R) (i) All upper bounds of {h, eh (iv) The least upper bound (LUB) or(h (v) All lower bounds of (b,c) (vi) The greatest lower bound (GLB) or(b, c} (b) Give complete reasons for the answers to the following (i)...
7n +(-1)" For the given sequence {anina, where an =- find 5n the least upper bound - LUB, the greatest lower bound - GLB and its limit, if they exist. a) There is no LUB, GLB = 0; Diverges 3 b) LUB 6 5 GLB = ; Converges to 7 5 9 2 6 7 c) LUB 3 2 GLB = Converges to 9 5 5 d) LUB 3 GLB = 2' 6 5 Diverges 7 6 e) LUB GLB...
Let G be a simple graph with at least four vertices. a) Give an example to show that G can contain a closed Eulerian trail, but not a Hamiltonian cycle. b) Give an example to show that G can contain a closed Hamiltonian cycle, but not a Eulerian trail.