Topology Help

[Galaxy]

I need some help with some Topology Homework. Here are the specific questions:

1. Let A and B be subsets of a topological space (X, *). Show that (X - Cl(A)) ∪ (X - Cl(B)) ⊆ X - Cl(A Intersect B). Find an example that shows these sets are not in general equal.

2. Let X = {a,b,c} and * = {X, ∅, {a}, {a,b}}. Let A = {a,c}.
Find: A' and find A ∪ A'

For 3 and 4 U is the usual topology for ℝ.

3. Let A = (0,1)∪(1,2] be a subset of (ℝ,U).
Fina A' and find A∪A'

4. Let A = [0,1)∪(2,3)∪{4} be a subset of (ℝ,U).
Find Cl(A) and find Int(A).

For 5 L is the open half-line topology for ℝ.

5. Let A = (-∞,1)∪[2,+&#8734 be a subset of (ℝ, L).
Find Cl(A) and find Int(A).

 

[Alex_J_Leon]

Looks like you got most of this answered already, except maybe not the last one. It looks like it'd be pretty easy if I knew what the heck was going on here lol.

I did look at some sample exams and stuff but yeah what is this for? A bit off topic >.>

 

[Galaxy]

Looks like you got most of this answered already, except maybe not the last one. It looks like it'd be pretty easy if I knew what the heck was going on here lol.

I did look at some sample exams and stuff but yeah what is this for? A bit off topic >.>

Haha... So you know how like geometry deals with shapes and all that jazz. Topology is kinda like that but deals with spaces more or less. Its kinda complicated. And the above questions were just practice problems I needed help with but I got it figured out.