Arab and Arabian are both related to people:        He is an Arab.   He is an Arabian.      Which is used for the location of a country?        Egypt is an Arab country.   Egypt is an Arabian country.
Are these adjectives interchangeable?  I always hear: 'An Arab man.' but never 'An Arabic man.' and I always hear 'Arabic coffee' but never hear 'Arab coffee.'
Is there a way to calculate the improper integral $\int_0^\infty \big(\frac{\ln x}{x - 1}\big)^2 dx$?  What have I tried:  $$\int_0^\infty \Big(\frac{\ln x}{x - 1}\Big)^2 dx = \int_0^1 \Big(\frac{\ln x}{x - 1}\Big)^2 dx + \int_1^\infty \Big(\frac{\ln x}{x - 1}\Big)^2 dx = \int_1^\infty \Big(\frac{\ln x}{x - 1}\Big)^2dx + \int_1^\infty\Big(\frac{\ln t}{\big(\frac{1}{t} - 1\big)t}\Big)^2dt = 2\int_1^\infty \Big(\frac{\ln x}{x - 1}\Big)^2dx$$  From the above statement we can conclude, that the integral does indeed converge, as $0 \leq (\frac{\ln x}{x - 1})^2 \leq \frac{C}{(x - 1)^{\frac{3}{2}}}$, for some constant $C$. However, this new form of the integral is not much helpful in finding its exact value.  I also tried substituting $z = \ln x$ , then $dz = \frac{dx}{x}$. Then the integral becomes reduced to $2\int_{0}^{\infty} \frac{z^2}{e^z(e^z - 1)^2}dz$, which, unfortunately, also does not seem to be any easier. I am interested in good integer approximation from below and from above for binary Log(N!).  and  provides only a general idea but not exact values. In other words I need integers A and B so that  A &lt;= Log(N!) &lt;= B Difference between "commit suicide" and "suicide" Attribute editing in QGIS on geoJson file We have vector files in the format of geoJson files. We need to keep it in geoJson format as it is picked up by mobile devices via Restful services.  The problem is we want to change the attributes of the features in QGIS but it seems like this is not possible. We don't have to add or remove columns. We simply need to edit the existing data.  Is there a work around for this?  Are there any plugins that I can download that will allow me to do this in QGIS? How to place a float at the top of a floats-only page? When closing a question as a duplicate there is a text box which says: "search, or enter a question link or numeric id". You can copy and paste a question link into here, but this fails if the URL starts with https:// instead of http://, with the message "Your search returned no matches; please try a different search". Why is the sky dark at night? The question is the well-known      If there are so many/infinite stars, in every direction, why is it dark at night? Where goes all the light we don't see?    Discussing with a friend we found different answers.   The first (my friend's answer) is that given the fact that in a finite amount of time (in this case, the age of the universe), light can travel only a certain, finite, distance, we cannot see, if they actually exist, stars farther than such distance (about 13 billions of years, I guess). Then he states (or better, I got him notice he implicitly does this)  that within this radius there aren't enough stars to fill the night sky, and that's why we have darkness without sun's light.   The second answer (mine, or anyway the one I heard from a minutephysics YouTube video) is that despite of the big size of the observable universe, cosmological expansion red shifts most of the light out of the visible radiation range, so that the majority of light can't be seen by our eyes at night, while if we use, for example, an infrared camera, we should see a brighter sky, and lenghtening more and more the wavelength at which we observe the sky, we come to the uniform background radiation.  So my question is, what is the right answer? Is it one of the above-mentioned or even a third one?  EDIT: I've seen both answer may be acceptable, but what is the main contributing phenomenon? I'm trying to remember the name of a series of books about a boy who works with dragons.  Dragon's blood (or maybe it was slobber?) is acidic, and the children who wrangle these dragons often end up with deep pock marks.  On this world, days are like ours but nights get very cold, requiring anyone stuck outside to find a shelter until dawn (not the false dawn)  The other thing I remember is that in one of the books by slicing open a dragon and spending the night, the character emerged with special dragon powers. Noncoalescing and bouncing droplets if you set a dish filled with water onto a loudspeaker or other vibrator and make vibration, When it oscillates, it is possible to hold small droplets on its surface for a long time. I mean, when you put a droplet of water on vibrating water surface, it doesn't coalesce with the water and bounce on the surface of water.( see this video  )  As we know, drop reaches its minimal potential when coalescing with water ( that's why drops coalesce)  what exactly cause this? why doesn't the drop coalesce with the water? which of the two it is? X,Y are independent exponentially distributed then what is the distribution of X/(X+Y) Been crushing my head with this exercise. I know how to get the distribution of a ratio of exponential variables and of the sum of them, but i can't piece everything together.  The exercise goes as this:  If X,Y are independent exponentially distributed with beta = 1 (parameter of the exponential distribution = 1) then what is the distribution of X/(X+Y)  Any ideas?  Thanks a lot. Simple enough question: What math should all game programmers have a firm grasp of in order to be successful?  I'm not specifically talking about rendering math or anything in the niche areas of game programming, more specifically just things that even game programmers should know about, and if they don't they'll probably find it useful.  Note: as there is no one correct answer, this question (and its answers) is a community wiki.  Also, if you would like fancy latex math equations, feel free to use . Is there a way to exclude other particle systems from the effects of a Wind effect? I have a scene with a number of particle systems. I'd like to have a separate wind effect for my main scene and another for an extra: an emitter + wind-effect to blow leaves into my scene. I can't find any way to exclude, so here I am. At the very worst, I can just render the main scene and then render the wind effect and composite it, but I figured I'd check first. I was confused initially about what the pins mean next to a topic in the new help center.  "those articles are "featured" articles; they are meant to draw attention to the most important site policies or most frequently encountered issues."   If the pin is used to denote an important topic, it should at least be noted as such. Also a pin generally means to me that this is something that I personally selected.  Could their meaning be clarified somehow? Drush hangs when trying to bootstrap Drupal Calculating slope in percentage with QGIS I'm working with QGIS, v. 2.0.1. I have several soil types. They are (amongst others) described with slope indications. I already calculated the slope from the DTM in degrees, but as description of the soil types is in percentage, I need to calculate the slope in percentage. I tried two things:  I tried the analysis tool from the raster section, but it didn't work. The result was just black with values from 0 to 0. The same happened when I tried to calculate the percentage in the raster calculator but the result was the same.  Maybe I need to say that the terrain is pretty plain. What else can I do? Update I tried the raster calculator and did what @radouxju suggested. It gave me a black picture with values from 1756.64 to 1756.64. But as soon as I click in the picture the values are &quot;normal&quot;, say 5.88 or 13.224 or something like that. The same happens when I try the gdaldem tool but with values from 0 to 0. I also tried to change the contrast enhancement (like stretch to min/max) but it didn't change anything. Update 2 I just  that maybe I have to set the scale to 111120  but that doesn't work neither (result: black, values 0-0). Prove that if $d$ divides $n$ then $φ(d)$ divide $φ(n)$ for $φ$ denotes Euler’s $φ$-function.  I know that $d|n$ mean there exists some integer $k$ such that $n=kd$, but how can I use this to prove $φ(d)$ divide $φ(n)$ Remember my "sort by" setting when browsing favorite site feeds Opening the menu and selecting an item from the "Favorite Sites" menu allows us to see a feed for a specific site. In the top right corner of this page is a drop-down which allows us to select the "sort order" for the posts. The default is "Active" with other options like "Newest", "Hot", etc.  The problem is that when I select "Newest" or any other option. This preference is not remembered when I change between a different "Favorite Site".  So I am requesting that the selection is persisted when changing between site feeds. I have no preference whether this is implemented per site (to allow a different default for each site) or just one single preferred default that works on all sites (last option selected). I just want it to remember that I have selected "Newest" when I am flicking though the sites. Let $G$ be an abelian group of order n.   Let $\mathbb{C}^*$ be the multiplicative group of non-zero complex numbers, and suppose $f:G \rightarrow \mathbb{C}^*$ is a homomorphism. Prove that $\sum_{g \in G} f(g) = 0$ or $\sum_{g \in G} f(g) = n$.  I can prove this for cyclic groups but am unable to generalise to all abelian groups. xslt, javascript and unescaped html entities i have a tiny little problem with xslt, js and html entities, eg. within a template:  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &amp;lt; 5; i++) {         //            ^^^ js error     } &lt;/script&gt;  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &lt; 5; i++) {         //            ^ xslt error     } &lt;/script&gt;  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     // &lt;![CDATA[     for (var i = 0; i &lt; 5; i++) {         //            ^ becomes &amp;lt;     }     // ]]&gt; &lt;/script&gt;   &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &lt;xsl:value-of disable-output-escaping="yes" select="string('&amp;lt;')"/&gt; 5; i++) {         // works of course     } &lt;/script&gt;   does anyone have an idea where my problem could come from? i always thought the xslt processor would leave the content of a &lt;script/&gt; element unescaped when using the html output method ...  i run libxslt2 version 1.1.24 on OSX which was installed using macportsports ...