Recent content by Maths Lover

I look for good books on solving partial diffrential equations (PDE's) using integral transforms specially Fourier and laplace transforms. Do you have any recommendations for such books? I don't look for a book concerned with the theory, rather, with the methods itself (a suitable book for a...

Homework Statement Suppose Y\subset X and X,Y are connected and A,B form separation for X-Y then, Prove that Y\cup A and Y\cup B are connected. The Attempt at a Solution I can show easily that at least one of Y\cup A or Y\cup B is connected. but I don't know how to show the...

Sure, I know that a function is continuous if the preimage of an closed set is closed. and a set is closed iff its closure is the set itself. I lately heared that an element x is in the closure of a set if every neighborhood of x intersects the set itself. a function is continuous iff for...

ِA function f:X \rightarrow Y between two topological spaces X and Y is continuous if the preimage of any open set of Y is an open set of X.

My question is: Let f:\bigcup_{\alpha}A_{\alpha} \rightarrow Y be a function between the topological spaces Y and X=\bigcup_{\alpha}A_{\alpha}. Suppose that f|A_{\alpha} is a continuous function for every \alpha and that {A_{\alpha}} is locally finite collection. Suppose that A_{\alpha} is...

I read so much to reach the point about golden members :D I understood that those members have some control about the contents on the the forum , is that all the story ?

If I want to post a new thread or a new post , and if my post needs some mathematical statement , say in first order logic then I need to use Latex to make my posts readable , but it seems that the site doesn't support LaTeX ! then What to do ? any suggestions ?

There is a notice on my page here which tells me that I can get a golden membership by making a link to Physics Forums on my Website or Blog. But What is a golden membership?! What is the difference between it and my membership now?!

Here is the question in attachment , I make it as the site don't support LaTeX I think! https://www.physicsforums.com/attachment.php?attachmentid=63439&stc=1&d=1383093152

yes , i can understand it now :) thanx

take this example ! 6 can't divide 3,4,5 but 6 can divide 3*4*5= 60 p can't divide any factor but maybe it can do this with some products of them like the example above ! why not ??

yes , I'm familiar with it ! can you explain how does this follows from the fundamental theorem of arithmetic ?

hi , this result is from text , Abstract Algebra by Dummit and foote . page 120 the result says , if G is a finite group of order n , p is the smallest prime dividing the order of G , then , any subgroup H of G whose index is p is normal and the text gave the proof of this result ...

prove , if x is a rational number , x ≠ 0 then , tan(x) is not rational this theorem was proved by a mathematician called Lambert , I search for the proof , anyone knows it ?!

what is nice ? the music or hobbies ?! hmm , I don't know this group " massar egbari " ! - can you tell me the name of one of them songs ? " nowdays , many types of songs is avaliable in egypt , but I don't prefer these new kinds , I like ancient singers ! like Fayrouz if you know her