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Sophomore Graduate Student in Mathematics


Jul
24
comment Continuous mappings pull back closed sets to closed sets
Definition of closed is that the a contains all its limit points where $a$ is a limit point of $X$ if for every open sphere $S_{\epsilon}\left(a\right)$ there exists an $x \in X$ such that $x \in S_{\epsilon}\left(a\right)$
Jul
24
comment Continuous mappings pull back closed sets to closed sets
Your second step would be true only for onto mappings, while the textbook says $f$ is an into mapping, or am I missing something?
Jul
24
revised Continuous mappings pull back closed sets to closed sets
Added the condition that the mapping is into.
Jul
24
comment Continuous mappings pull back closed sets to closed sets
But the mapping is an into mapping, how do I know $f^{-1}$ exists for all Y
Jul
24
asked Continuous mappings pull back closed sets to closed sets
Jul
21
revised How to prove that f is discontinuous at one point at least
deleted 475 characters in body
Jul
21
revised How to prove that f is discontinuous at one point at least
added 252 characters in body
Jul
21
answered How to prove that f is discontinuous at one point at least
May
13
awarded  Quorum
Mar
29
accepted Possible error about properties of boundary points in Simmons's Topology and Modern Analysis
Mar
29
asked Possible error about properties of boundary points in Simmons's Topology and Modern Analysis
Jan
17
comment Difficulties with Chapter 2 in Rudin
@Adam: I tried to have a go ;-). Was not very comfortable. Will try again after reading some more.
Jan
13
revised Difficulties with Chapter 2 in Rudin
deleted 5 characters in body
Jan
13
revised Difficulties with Chapter 2 in Rudin
added 785 characters in body
Jan
13
accepted Difficulties with Chapter 2 in Rudin
Jan
12
awarded  Commentator
Jan
12
comment Difficulties with Chapter 2 in Rudin
thanks... expecially for the problems, though I will need some time. But I'll get back to you as soon as I can.
Jan
12
comment Difficulties with Chapter 2 in Rudin
"Because the subject is relatively standard, other texts may provide a different perspective on a topic that provides you with that "ah-ha" moment -- why have one teacher when you can have many? " Yeah, though so, but I was afraid, (see my comment on answer by Samuel Reid about multivariable calculus book.) Hence, I was kind of reluctant. But, I will try now, I have Royden with me. I will get korner if possible and see.
Jan
12
comment Difficulties with Chapter 2 in Rudin
thanks for the clarification, was just browsing through one of the multivariate calculus book, they said the same thing about compactness as described by Samuel Reid, so I had an idea, but kahen's explanation clarifies it. Thank You! Anyway, that is cleared now. But, boy, was I confused when I read that book!!
Jan
12
comment Difficulties with Chapter 2 in Rudin
+1 : Thanks. I am an electrical engineer too. I was good in mathematics in school and have a decently good olympiad experience, and so thought that I may be able to handle Rudin well ;-). I will take your advice of keeping other books as supplement. Thanks for your advice.