10327/Homework Assignment 7

Reading
Read sections in Munkres' textbook (Topology, 2nd edition). Remember that reading math isn't like reading a novel! If you read a novel and miss a few details most likely you'll still understand the novel. But if you miss a few details in a math text, often you'll miss everything that follows. So reading math takes reading and rereading and rerereading and a lot of thought about what you've read. Also, preread sections , just to get a feel for the future.
Doing
Solve and submit the following problems from Munkres' book:
 Problem 1 on page 199.
 Problem 1 on page 205.
 Problems 1, 4, 5, 8, 9 on pages 212213.
Remark. The following fact, which we will prove later, may be used without a proof: If is a topological space and are continuous functions, then the sum is convergent and defines a continuous function on .
Due date
This assignment is due at the end of class on Thursday, November 25, 2010.
Dror's notes above / Student's notes below 
 Question: In problem 1 p205, is asks us to show that any closed subspace of a normal space is also normal. Do we really need the condition that the subspace be closed?  Jdw
 Yes. Drorbn 19:14, 19 November 2010 (EST)
Questions by Kai Xwbdsb 21:26, 19 November 2010 (EST) were moved to Classnotes for Thursday November 18 as they are about that class and not about this assignment. Drorbn 06:03, 20 November 2010 (EST)
 Question. If we have a finite set of continuous function mapping from any topological space into the reals. Any linear combination of these continuous function is still continuous right? The proof is a little extension of 157 proof. This is used to prove the statement you mentioned above. KaiXwbdsb 17:14, 20 November 2010 (EST)
 Any linear combination of functions from (an uncountable set unless X is empty) is continuous. On its own, however, this proves nothing about infinite sums. Bcd 22:32, 21 November 2010 (EST)