Preparing for Quals in Math I will be starting graduate school next semester in mathematics and I have no idea how I am going to fare. My goal for this summer and I am slowly making progress is to go over topics in real analysis, topology and algebra. I am also doing an individual study in multivariable calculus which also covers analysis and linear algebra as well. My big question, which is very broad is, how does one prepare for the quals?
What kind of questions can I expect to see on a qualifying exam? In mathematics, there are certain open questions which are the subject of current research (think of the newest papers in the top journals).  I have also heard that some graduate programs ask questions such as these on their qualifying exam.  How common is this practice?  What kinds of questions can I expect to see on a qualifying exam?  I know that a qualifying exam typically tests the knowledge gained in graduate school, but I'm not sure to what extent this knowledge is tested?  How "advanced" should I expect these questions to be?
I was looking at coreutils and found this as one of the files included as part of coreutils:  /usr/bin/[. What is [ and what does it do? It is an executable. I just don't know what it does or how to use it. $ file /usr/bin/[   /usr/bin/[: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared  libs), for GNU/Linux 2.6.15, stripped    When I try to run it, I think it is defaulting to the bash built in line expansion. Instead of actually running the file. $ &quot;/usr/bin/[&quot; /usr/bin/[: missing ‘]’ $ /usr/bin/\[ /usr/bin/[: missing ‘]’ Can $(X_1,X_2) \cap (X_3,X_4)$ be generated with two elements from $k[X_1,X_2,X_3,X_4]$? Can $(X_1,X_2) \cap (X_3,X_4)$ be generated with two elements in the ring $R=k[X_1,X_2,X_3,X_4]$? Can it be generated with three elements? (Here $k$ is a field.)    Thanks for any help. Windows using too much RAM, how to diagnose resource hog I have 16GB of system RAM. On startup with no applications open except the task-manager Windows is using about 3gb of RAM. I looked in the processes tab, but nothing seems to be out of the ordinary. How can I find out why my Windows is using so much RAM.    all processes from all users      Reading from the poolmon it seems that my wireless broadcom driver is using about 0.4GB of of RAM. Even if I remove  it would still be using  2.6GB on start-up, which is still too much.      After reinstalling the wireless driver associated with the memory leak. I have a new screenshot and would like to confirm that it was indeed a memory leak. I have a vocabulary like this:   Parent 1  Child 1 Child 2 Child 3   Parent 2  Child 1 Child 2    Now I would like to use a view to create a list of a Parent term with its Child terms. I try to do this with Views UI, but only show the term parent... No the child term's. It is very confusing for me.  Can anyone help with this case? Thanks :D On what criteria should I evaluate domain registrars? Though I've been a web developer for a fair amount of time, I am going for the first time to buy a few domain names.  I have looked into the domains I'm going to buy and know that they're available, and I've been looking into which sellers to use.  After doing a lot of research, the main ones I'm considering are 1&amp;1, Namecheap, and Gandi.  The problem is, when continuing to research, I'm not really sure what makes one domain seller distinct from another.  I don't need much in the way of services--definitely not hosting, since I plan to use Heroku for that.  I mainly only need the domain itself and DNS management, as well as possibly SSL certificates and WHOIS protection.  Question:  What makes one domain seller different from another?  How can I go about evaluating which one is the best for me?  Note:  This question is not which domain seller is the best, but rather, what criteria can I use to evaluate them and rank one over another.  I'm trying to find out what makes one domain seller different from another, since they all seem to be pretty similar to me right now. Why is using "for...in" for array iteration a bad idea? valueOf() vs. toString() in Javascript What does the colon in Tikz coordinates mean? How to use Whatsapp mobile application on Ubuntu Touch? In my Android I have "Whatsapp" application running. But mobile freak I am not, and specially the mobile keyboards.  So how can I run my same application, same account from my Ubuntu desktop PC?   Follow up:  Just to do keyboard routing, i have used . Which allows me to takeover the Android input fields access via web link to type in my PC keyboard, and then it re-route the keys to Mobile.  Features:   Allows me to copy and paste large texts to Android input fields without using the keyboard of Android but simply using my Desktop PC, via web link http://android.ip.address.goes.here:port/ Allows me to have key submit which is similar to key press of mobile set itself   At-least works without having mobile in rooted. Hope it helps you!! How to calculate the Fourier transform of a Gaussian function? I would like to work out the Fourier transform of the Gaussian function   $$f(x) = \exp \left(-n^2(x-m)^2 \right)$$  It seems likely that I will need to use differentiation and the shift rule at some point, but I can't seem to get the calculation to work. Does anyone have any advice?  By the way, I am using   $$\mbox{FT}(f)(k)=\int_{-\infty}^\infty f(x)e^{-ikx}\,\mathrm d x$$  as my definition of a Fourier transform. Many thanks. What are the guidelines for reviewing? About reviewing The review queues contain posts that possibly need further action from the community, like improvement, closure or deletion. By presenting those posts for peer-review, the system aims for higher quality content. Some user actions, such as suggesting an edit, casting a flag, close vote or reopen vote, or posting for the first time, can trigger the inclusion of a post on a review queue. There are also posts included on the queues algorithmically, such as the contents of Late Answers and Low Quality Posts. General guidelines  Always read the full post you are reviewing. Don't rush. Take the necessary time to read the post carefully. If you don't care about a post, just click Skip or Not sure. When you need more context, open the post link to see the question and all answers. Most posts coming up for review can be improved. Use the Edit option, and edit thoroughly. If you're unsure how to review a post (perhaps it's outside your areas of expertise), skip it. Someone who understands it better will review it later.  Guidelines for specific review queues         (Stack Overflow only) Bibliography style elsarticle-num-names with DOI and hyperlinks but no explicit url I prepared my article with elsarticle, using \citep &amp; \citet throughout. I originally used apalike bibliographystyle but now need to change it to elsarticle-num-names for citation formatting requirements (see point #2 below).  Now, I am attempting to make 2 changes:     add DOIs to the bibliography change reference style to [1] for \citep and Author et al. [1] for \citet.   I want to keep hyperref and do not want explicit URLs (only DOIs) but cannot make this work!  Thank you for any help you might have!  MWE:  \documentclass[preprint,12pt]{elsarticle} %\usepackage{hyperref}  \journal{Test Journal} \begin{document} \begin{frontmatter} \title{The Title} \author{Prof. Big Ol' Wanker} \address{123 Happy Lane} \begin{abstract} TEXT \end{abstract} \begin{keyword} keyword 1 \sep keyword 2 \sep keyword 3 \end{keyword} \end{frontmatter}  \section{SECTION1TEST} \noindent cite: \cite{Richards1931} \\ citep: \citep{Richards1931} \\ citet: \citet{Richards1931} \\  \bibliography{library} \bibliographystyle{elsarticle-num-names}  \end{document}   Here is the reference for Richards1931 from my library.bib file:    @article{Richards1931, author = {Richards, LA}, doi = {10.1063/1.1745010}, file = {:D$\backslash$:/Papers/Richards - 1931 - Capillary Conduction of Liquids Through Porous Mediums - Journal of Applied Physics.pdf:pdf}, issn = {01486349}, journal = {Journal of Applied Physics}, pages = {318}, title = {{Capillary Conduction of Liquids Through Porous Mediums}}, url = {http://scitation.aip.org/content/aip/journal/jap/1/5/10.1063/1.1745010}, volume = {1}, year = {1931} }   without hyperref (wanted hyperlinks present, DOI displays correctly, but unwanted URL is present):    with hyperref (hyperlinks not present, DOI displays incorrectly, and unwanted URL is present): Different font color for question status => closed <= When I stared at  () and I even thought [question refined] as offical status of the post.    &lt;somebody  it now, So, I've edited this question to get same effect>  How about official status [closed] as   different font color or  different font size or put the text [closed] outside the question link   Or   put a special tag as suggested in the    to clarify from those? Why can the last block contain a full block of padding in CBC Encryption? I'm trying to understand the SSL Poodle Attack and I'm wondering why the last block of a CBC Record can be full of padding? Wouldn't that mean that the useful data was already a multiple of the key size?  Maybe I'm misunderstanding something else here, as it would seem like you can pad by any number of full blocks of padding. Just don't see why an SSL Library would do that.  Thanks! How to read ext4 partitions in Windows? I have two questions on ext4:   Is there currently a way to mount an ext4 partition in Windows (XP/Vista/7) to get basic read support? If not, are there any plans to support this someday? UITextField - capture return button event How large would the steam explosion at Chernobyl have been? So the  of the HBO series began to cover the  that led to them sending three divers into the water below the reactor to drain the tanks.  This occurred after the initial explosion that destroyed the reactor, and after the fire in the core had been put out. But at this point the decay heat and remaining fission reaction kept the core at more than 1200°C, causing it to melt through the concrete floors below the reactor.  And below the reactor were water tanks which contained 7,000 cubic meters of water (according to the TV show. If anyone has a real figure, I'd love to hear). When the lava of the melted core hit it, it would cause an enormous .  Finally, my question: About how large would this explosion have been? The character in the show says "2-4 megatons" (of TNT equivalent, I assume). I'm pretty sure this is absurd and impossible. But real estimates are hard to come by. Other sources vary wildly, some repeating the "megatons" idea, and others saying it would've "". This still seems crazy.  tl;dr:  I know a lot of it hinges on unknowns and the dynamics of the structures and materials involved, so I can simplify it to a constrained physics question:  Assuming 7,000 cubic meters of water instantly flashes to steam, how much potential energy is momentarily stored in that volume of steam occupying the same volume as the water did?  I don't know what to assume the temperature of the steam is. There were hundreds of tons of core material at temperatures near 1200°C, so worst case scenario you could assume all the steam becomes that temperature as the materials mix. Best case scenario, I guess we could assume normal atmospheric boiling point (100°C)? How should I install HPLIP binary/proprietary plugin/driver for my HP printer or printer+scanner? shortcut key to detach a tab in firefox (move tab to new window) In FF, I can move a tab to a new window by either dragging the tab out of the browser, or right clicking the "move to New window" option from the context menu. is there a shortcut key to move the current tab to a new window without dragging or using the context menu, or a way to set one up?  Often, I like to look at 2 tabs side by side, so I drag one out, then hit WINDOWS KEY+→ to put the detached tab on the right, then ALT+TAB to tab back to the main window, then WINDOWS KEY+← to put the main window on the left. It would be great if I could do the whole process on the keyboard.  I checked  documentation and did not find any shortcut key for detaching a tab: Hair Paricle System not rendering properly on plane