1. anonymous

2. anonymous

@jtvatsim

3. anonymous

@zzr0ck3r

4. zzr0ck3r

I am having the same problem as last time. I can't open it. I will be right back, my wife needs some help.

5. anonymous

can you open it now?

6. zzr0ck3r

nope

7. zzr0ck3r

I only have wordpad on this pc.

8. anonymous

ok. let me post it one by one but its up to ten

9. anonymous

1 Let X= {x,y} and T=ϕ,X,x .Determine the closed set a)X b) X,{y} c)X,ϕ,y d) x,y

10. zzr0ck3r

take a screen shot and post the jpg.

11. anonymous

ϕ means empty set

12. anonymous

i choosed c

13. zzr0ck3r

$$\emptyset$$

14. zzr0ck3r

Should it say $$\mathcal{T}=\{\emptyset, X, \{x\}\}$$ ?

15. anonymous

yes that is the topology

16. anonymous

the question is what are the closed sets?

17. zzr0ck3r

sec, can you post a pic? I am not sure if I am getting everything. I think it is missing a bunch of $$\{,\}$$.

18. anonymous

$\let X={x,y} and ....T={\emptyset,X,x}$ what are the closed sets

19. zzr0ck3r

x is not a set here. should it say $$\{x\}$$?

20. zzr0ck3r

Sorry man, this all makes a huge difference. I cant answer without seeing the question. as it is posted it cant be answered. $$\{X,\{y\}\}$$ is weird...

21. anonymous

22. anonymous

may be it was a typo error. they din't close i think they out to

23. anonymous

@zzr0ck3r

24. zzr0ck3r

the only thing that is a set is X and it is closed.

25. zzr0ck3r

The other choices are not sets.

26. zzr0ck3r

And if they are they are not subsets of the space X, and thus are not closed with respect to the given topology

27. anonymous

assuming the the question was set correctly, what option should have been correct ?

28. zzr0ck3r

These questions are all messed up, they dont make sense...

29. zzr0ck3r

for something to be closed, they need to be a subset of the space, the only thing that was a subset of the space was the space itself.

30. anonymous

which implies that it out to be A

31. zzr0ck3r

yes, but the others are not even defined. I think where ever you got this, there is a problem with displaying all the characters.

32. zzr0ck3r

the thing they call a topology is not even a topology, as a topology is a set, and must have parentheses around it.

33. anonymous

ok thanks

34. zzr0ck3r

since I assume there should be parentheses, well then I dont know if they mean for there to be parentheses on other things, and without that information this cant be answerd.

35. anonymous

A space (X,Td) is called____________ if and only if (i) ϕϵ (ii) T contain open set whose compliment are finite sets discrete topology indiscrete topology cofinite topology metric topology

36. anonymous

i think indiscrete topology

37. zzr0ck3r

you are not listening when I tell you that I cant answer anything from that page. If you have something else I will gladly help, but theses questions are messed up. Ill check back tomorrow.

38. anonymous

sir, in the first question i asked . i assume that the option B is not correct because ,it is not in T. right ?

39. anonymous

i.e {y} is not in T