Determine unknown projection coordinates
Identifying Coordinate System of Shapefile when Unknown?
About an Hour ago, I faced a problem and tried different ways to solve it.  At last I was going to post my Question on Stack Overflow, but the last trick which came in my mind worked, and the problem got resolved.    Now, if I want to post that problem on Stack Overflow with the solution which worked for me, for the purpose to help other newbies to get their answer if they face the same problem, what is the proper way of posting such solution to a problem? Multivariable Delta Epsilon Proof $\lim_{(x,y)\to(0,0)}\frac{x^3y^2}{x^4+y^4}$ --- looking for a hint I have the limit $$\lim_{(x,y)\to(0,0)}\frac{x^3y^2}{x^4+y^4},$$ and would like to show with an $\epsilon-\delta$ proof that it is zero. I know with a situation like $$\left|\frac{x^4y}{x^4+y^4}\right|\leq y$$  or something similar, but I can't find a way to do the same thing here, as no single term in the numerator is of sufficient degree, although I think I could get this with a small hint. Generating list of manually installed packages and querying individual packages I'd like to get a list of packages installed manually by apt or aptitude and be able to find out whether a foobar package was installed manually or automatically. Is there any neat way of doing that from the command line? Hint proving this $\sum_{k=0}^{n}\binom{2n}{k}k=n2^{2n-1}$ I need hint proving this $$\sum_{k=0}^{n}\binom{2n}{k}k=n2^{2n-1}$$ Mathematician learning theoretical physics How to split a string with any whitespace chars as delimiters What regex pattern would need I to pass to  java.lang.String.split()  to split a String into an Array of substrings using all whitespace characters (' ', '\t', '\n', etc.) as delimiters? I am able to produce a standard length \sim with a tiny S above it, but I would like the \sim tilde to be longer (maybe one and half times as wide as a capital letter).  Any tips on how to change the width/length of \sim? How do I become a Werewolf? I've heard that one of (maybe the only?) secret races in this game is a werewolf.  How do I become a werewolf?  And by extension, how do I cure lycanthropy, that is, if there even is a cure? How to format numbers as currency strings How do I troubleshoot random rebooting? What items are mutually exclusive between worlds? As of 1.2, some features are mutually exclusive between worlds.  In the case of ores at least, .  However, a  gives you the chance for a  (and the upgraded Sweetheart Necklace) which does not seem to have an equivalent version in the Corruption.    What items, if any, are truly mutually exclusive in function between worlds? Whenever we have a changing magnetic flux through a conductor an induced electric field is generated. It is often said that these induced electric field lines are circular in shape.But why is this so?Why are these field lines not elliptical for example? How can this shape be mathematically derived?  Also does this have anything to do with equipotential surfaces?Do such non-conservative electric fields even produce a potential field?If not why? Blank white desktop icons on new Windows 7 install I just did a fresh install of Windows 7 professional on my father's Toshiba Satellite laptop and everything went smoothly except for the fact that certain desktop shortcuts appear as a blank white page.    I've tried:    going in and changing the icon to many different things reloading the icon cache by deleting the IconCache.db file uninstalling his Free AVG as he heard the virus scanner might be preventing it (it wasn't and he put it back.)   The one thing these icons have in common is that they are shortcuts to some very old DOS executables.  One of them is Word Star 2000 to give you an idea.  Does anybody have any other suggestions besides what we've tried? Where to put the escape characters? I've tried to change my prompt by editing .bashrc:  export PS1="\e[0;32m[\u@\h \W]\$ \e[m"   This seems to work, but ctrl-r to access reverse history ends up with my typing not appearing in the same place as it will be interpreted (like ). It is fine when using the up or down arrows to select previous commands though.  I've had a look at that question, but can't seem to work out where to apply the escape characters in my prompt. I've tried a few combinations but then I break normal text typing functionality or simple back/forwards through history.  If you could include an explanation of which instances of characters need escaping and why, that would help me (and hopefully others) learn. Index not created in pdf output, even though idx file is present I have a document that has \usepackage{makeidx} and \makeindex in the preamble and \printindex inside the document body. An .idx file is created when I compile, no errors are signalled, still there is no index listing in the PDF document that is produced. There used to be one until all my files were deleted except the .tex file, after that I could not get the index to appear in my output. How can one troubleshoot this thing? I have changed all the "%bm" with "%tm" wherever I could find it in the build profiles (Tools -> Options -> Clean), as Thorsten Donig suggested on this website (in an answer to another posting regarding problems with the index creation). It did not solve my problem. I am using the TeXnicCenter editor on Windows XP, with the MiKTeX 2.9 distribution. Hydraulic Disk brake piston not fully retracting My front disk brake's piston doesn't fully retract.  While I can ride the bike, the brake is slightly rubbing.  (IE, if I just spin the wheel with my hand, it'll go around about one and a half times and then stop.) It's definitely slowing me down.   If this fixable?  The advice I got was that it's not worth the trouble and to buy a replacement set.  The current brakes are Avid Juicy 7s that are about 7 years old I'm new to field extensions and I can neither see why or how to prove this statement.  If I'm not mistaken, to construct a splitting field, you construct rupture fields one after the other, using that the $8$ element field is the splitting field of $X^8-X$ over $\mathbb F_2$, since $2$ is the only prime divisor of 8.  Over $\mathbb F_2$ $X^8-X$ has two roots : $0$ and $1$. Therefore $X^8-X=X(X-1)(1+X+...+X^6)$. The last factor, call it $P$, has no roots. So let $\alpha$ be a root in some extension $\mathbb F_2(\alpha)$ of $\mathbb F_2$.  We now have $P=(X-\alpha)(X^5+\alpha X^4+...+\alpha^4X+\alpha^5)$.  I suspect $\alpha$ might not be the way to go and if so, my second plan would be to reduce $P$. I don't know how to do this but assuming it to be done, hence having $P=P_1...P_n$, I could start using $P_1$'s rupture field, and then my best guess is that if $\mathbb F_2[X]/(P_1)$ is not sufficient, I re-reduce $P$ over this new field and consider the rupture field of one of the factors, and so on.  Now assuming I wasn't given the statement itself, is it elementary to construct the $8$ element field using $\mathbb F_2$ ? I have recently installed lubuntu 11.10 on my old laptop (acer aspire 5315 celeron) and observed that fan is not working properly on lubuntu side.I find it strange that it is working perfectly under window vista.   How could I solve this problem? How can I create a custom terminal command (to run a script)? Confirming that my own question is a duplicate by voting to close should have immediate effect