please help

- anonymous

please help

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- schrodinger

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- anonymous

##### 1 Attachment

- anonymous

@jtvatsim

- anonymous

@zzr0ck3r

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## More answers

- 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.

- anonymous

can you open it now?

- zzr0ck3r

nope

- zzr0ck3r

I only have wordpad on this pc.

- anonymous

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

- 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

- zzr0ck3r

take a screen shot and post the jpg.

- anonymous

ϕ means empty set

- anonymous

i choosed c

- zzr0ck3r

`\(\emptyset\)`

- zzr0ck3r

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

- anonymous

yes that is the topology

- anonymous

the question is what are the closed sets?

- zzr0ck3r

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

- anonymous

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

- zzr0ck3r

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

- 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...

- anonymous

##### 1 Attachment

- anonymous

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

- anonymous

@zzr0ck3r

- zzr0ck3r

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

- zzr0ck3r

The other choices are not sets.

- zzr0ck3r

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

- anonymous

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

- zzr0ck3r

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

- 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.

- anonymous

which implies that it out to be A

- 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.

- zzr0ck3r

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

- anonymous

ok thanks

- 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.

- 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

- anonymous

i think indiscrete topology

- 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.

- anonymous

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

- anonymous

i.e {y} is not in T

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