Topology
Prove or disprove ( with a counterexample)
(a) The continuous image of a Hausdorff space is Hausdorff.
(b) The continuous image of a connected space is
connected.
Topology question:
Show that a function f : ℝ → ℝ is continuous in the ε − δ
definition of continuity if and only if, for every x ∈ ℝ and every
open set U containing f(x), there exists a neighborhood V of x such
that f(V) ⊂ U.
Let X be a non-degenerate ordered set with the order topology. A
non-degenerate set is a set with more than one
element.
Show the following:
(1) every open interval is open, (2) every closed interval is
closed, (3) every open
ray is open, and (4) every closed ray is closed.
Please note: Its a topology question.
Show that any open subset of R (w. standard topology) is a
countable union of open intervals. Please explain how to do, I only
understand why it is true.
What is required to fully prove this. What definitions should I be
using.
Show that every permutational product of a finite amalgam
am(A,B: H) is finite.Hence show that every finite amalgam of two
groups is embeddable in a finite group.
Please justify below questions (its a topology question) with
valid arguments:
1. Show that an infinite set is not finite.
2. Is there an infinite set which is not countably in
finite?
Thanks in advance.