Get date of Monday in current week in PHP 4
Get date for monday and friday for the current week (PHP)
We all use mathematical induction to prove results, but is there a proof of mathematical induction itself? I just realized something interesting. At schools and universities you get taught mathematical induction. Usually you jump right into using it to prove something like   $$1+2+3+\cdots+n = \frac{n(n+1)}{2}$$  However.  I just realized that at no point is mathematical induction proved itself? What's the mathematical induction's proof? Is mathematical induction proved using mathematical induction itself? (That would be mind blowing.) What is the difference between apt and apt-get? How to re-link missing blender files I have multiple characters linked to a blender file, but i moved the original character files and now blender is sating they're missing.  Is it possible to get blender to find the missing blender files like it finds missing image files so that i can preserve the previously made animation?  On a side note is there a way to also view a list of all the missing files? I have  a  requirement where a future method need to be called from batch apex ,I came across various articles stating that a future method could not be called from the batch. Is there any alternate solutions for that? Changing my Apple ID's email: address is not available "X Department" versus "Department of X" I would like to know whether these phrases "English Department" and "Department of English" have the same meaning. Thanks! How do I check whether a module is installed in Python, and install it if needed? In terminal, after I start Python, how will I know what are the modules present in python? Suppose I need to learn the modules NumPy and SciPy.   How will I install it if it is not installed?  How will I know if it is already installed? How do I solve this limit: $\lim _{x \to 0} \left(\frac{ \sin x}{x}\right)^{1/x}$? $$\lim _{x \rightarrow 0} \left(\frac{ \sin x}{x}\right)^{1/x}$$  I have spent an hour on the above limit and have no work to show. I tried using L'Hopital's Rule, but just kept going around in circles. Any help would be appreciated. Thank you. Installed Ubuntu alongside Windows 8, and W8 won't boot anymore Cropping Shapefiles in QGIS? I need to clip a large and very detailed shapefile in QGIS showing environmental data similar to a temperature map.   Is there something like the very simple crop tool like in Adobe Photoshop where you can drag a rectangle over an area of interest and crop the shapefile to this area only?  I do have an additional shapefile of neighborhoods/districts that I could also use for cropping but I do not know how to specify "extract a shp/kml only within the borders of district X, row xxxxx in the attribute table of districts.shp"  How can I extract the data primitively within a rectangle of choice or per district?  I need smaller pieces from the large map that has been provided by an environmental geo-institute to be implemented into an mobile Application (Android) to view the quite heavy data in a lighter way.   I made some screenshots of the data and posted them here: .  You can see the districts and the data layers. I need to have every district as a separate file / separately export every dataset per district to KML. Bookmark panel in Chrome/Chromium like in Firefox Weird http -> https redirection although not configured I am running Apache 2.2.15 (CentOS 6.6) with a HTTP-only domain   demo.xml-director.info  Using wget I can retrieve the content properly   wget -S http://demo.xml-director.info --2015-01-05 13:31:41--  http://demo.xml-director.info/ Resolving demo.xml-director.info (demo.xml-director.info)... 176.9.146.28 Connecting to demo.xml-director.info (demo.xml-director.info)|176.9.146.28|:80... connected. HTTP request sent, awaiting response...    HTTP/1.1 200 OK   Date: Mon, 05 Jan 2015 12:31:41 GMT   Server: Zope/(2.13.22, python 2.7.6, linux2) ZServer/1.1   Content-Length: 20227   Expires: Sat, 01 Jan 2000 00:00:00 GMT   Content-Type: text/html;charset=utf-8   X-Ua-Compatible: IE=edge,chrome=1   Content-Language: en   Vary: Accept-Encoding   Keep-Alive: timeout=15, max=100   Connection: Keep-Alive Length: 20227 (20K) [text/html] Saving to: 'index.html.4'   However Chrome/Firefox always change the request from http to https because of HTST. However for this particular domain there is no HSTS configured.  The server runs SSL for www.xml-director.info with enabled HSTS support. However there is further alias here that would map demo.xml-director.info to www.xml-director.info.   How can this problem be resolved.  VHOst for www.xml-director.info:  &lt;VirtualHost *:443&gt;     ServerName www.xml-director.info     ServerAlias xml-director.info      SSLEngine on     SSLCertificateFile /etc/httpd/certs/15742445repl_2.crt     SSLCertificateCHainFile /etc/httpd/certs/15742445repl_2.ca-bundle     SSLCertificateKeyFile /etc/httpd/certs/zopyx.com.key      CustomLog /var/log/httpd/xml-director.info.log combined     DocumentRoot /var/www/xml-director/landing-v1      Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains"      &lt;location "/"&gt;         Options +Indexes         Header set Access-Control-Allow-Origin "*"         Header set Access-Control-Allow-Methods "GET,PUT,POST,DELETE"     Header set Access-Control-Allow-Headers "X-Requested-With,Content-Type"     &lt;/location&gt;  &lt;/VirtualHost&gt;  &lt;VirtualHost *:80&gt;     ServerAlias www.xml-director.com      ServerAlias www.xml-director.info     ServerAlias www.xml-director.de     ServerAlias xml-director.com     ServerAlias xml-director.info     ServerAlias xml-director.de      RedirectPermanent / https://xml-director.info/ &lt;/VirtualHost&gt;   and for demo.xml-director.info  &lt;VirtualHost *:80&gt;     ServerName  demo.xml-director.info     RewriteEngine On      RewriteRule ^/(.*) http://127.0.0.1:12020/VirtualHostBase/http/demo.xml-director.info:80/xml-director/VirtualHostRoot/$1 [L,P]     RewriteRule ^/$    http://127.0.0.1:12020/VirtualHostBase/http/demo.xml-director.info:80/xml-director/VirtualHostRoot/$1 [L,P]      CustomLog /var/log/httpd/demo.xml-director.info.log combined     AddOutputFilterByType DEFLATE text/html text/xml text/plain text/css text/javascript      CacheRoot /tmp/cache     CacheEnable disk /     CacheIgnoreCacheControl on      KeepAliveTimeout 15     KeepAlive on      ExpiresActive On     ExpiresByType image/gif "access plus 10 day"     ExpiresByType image/jpg "access plus 10 day"     ExpiresByType image/jpeg "access plus 10 day"     ExpiresByType image/png "access plus 10 day"     ExpiresByType text/javascript "access plus 10 day"     ExpiresByType text/html  "access plus 1 hour"     ExpiresByType text/html  "access plus 1 hour"     ExpiresByType text/css  "access plus 10 days"      &lt;Location "/"&gt;         Order allow,deny         Allow from all     &lt;/Location&gt;  &lt;/VirtualHost&gt; Does the Planck scale imply that spacetime is discrete? On a quantum scale the smallest unit is the , which is a discrete measure.  There several question that come to mind:   Does that mean that particles can only live in a discrete grid-like structure,  i.e. have to "magically" jump from one pocket to the next? But where are they in between? Does that even give rise to the old paradox that movement as such is impossible (e.g. )? Does the same hold true  for time (i.e. that it is discrete) - with all the ensuing paradoxes? Mathematically does it mean that you have to use difference equations instead of differential equations? (And sums instead of integrals?) From the point of view of the space metric do you have to use a discrete metric (e.g. the ) instead of good old Pythagoras?   Thank you for giving me some answers and/or references where I can turn to.  Update: I just saw this call for papers - it seems to be quite a topic after all: Is Reality Digital or Analog? FQXi Essay Contest, 2011. , , . One can find some pretty amazing papers over there. I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the &quot;official  requirements&quot;, the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below. Which databases use real multidimensional indices? Is oracle ever using several indices to get data from tables, or will it always take the one that seems to have the highest selectivity? How about other dbms? The app forgets that I voted when I scroll the question Related:   I am using 1.0.71 on KitKat.  Immediately after voting, the arrow is displayed in red and the vote count is correct. However, when I scroll to read answers and then back to the top, the arrow is grey again and the vote count is reset to the previous value.  A reload of the question (pulling the finger down) is needed to show the correct situation, which is kept from then on.  This case was on security.stackexchange.com but I observed the same behavior on other sites too.  Screenshots   original state:  upvoted:  scrolled down and back up  after a reload What should I do if I want to be able to run a given program regardless of my current directory? Should I create a symbolic link to the program in the /bin folder? How is the equation of motion on an ellipse derived? Getting MAC Address I need a cross platform method of determining the MAC address of a computer at run time.  For windows the 'wmi' module can be used and the only method under Linux I could find was to run ifconfig and run a regex across its output.  I don't like using a package that only works on one OS, and parsing the output of another program doesn't seem very elegant not to mention error prone.   Does anyone know a cross platform method (windows and linux) method to get the MAC address?    If not, does anyone know any more elegant methods then those I listed above? Short connection at IAD (Dulles international airport) I am flying from New Orleans to Dulles (IAD) on United Express, and from IAD to Frankfurt on United. I have a short connection (45 minutes) in IAD.   I'm trying to figure out how can I make it:  Will I need to go throughout security and border check since I'm leaving the US? How big is IAD airport? and are there different terminals for domestic and international flights? If so, how long would it take to walk between them?