Why is it that whenever I decide to answer some question on Stack, some of the questions do not pop answer box for me to contribute in the solution? Do I need reputations even to answer a question!!
Questions can be closed or marked as duplicates.  What does it mean for a question to be &quot;closed&quot;? What does it mean for a question to be marked as a &quot;duplicate&quot;? Who can close a question? What are the reasons for closing a question ? Is closure the end of the road for a question? When are closed questions eligible for deletion?   Related        For more information, see &quot;&quot; in the .
Are there any disadvantages to always using nvarchar(MAX)? In SQL Server 2005, are there any disadvantages to making all character fields nvarchar(MAX) rather than specifying a length explicitly, e.g. nvarchar(255)? (Apart from the obvious one that you aren't able to limit the field length at the database level) Is there a safe way to run a diff on two zip compressed files? Seems this would not be a deterministic thing, or is there a way to do this reliably? Show that $3p^2=q^2$ implies $3|p$ and $3|q$ This is a problem from "" (specifically, exercise set 2 #9), which is one of my math texts. Please note that this isn't homework, but I would still appreciate hints rather than a complete answer.  The problem reads as follows:     If 3p2 = q2, where $p,q \in \mathbb{Z}$, show that 3 is a common divisor of p and q.   I am able to show that 3 divides q, simply by rearranging for p2 and showing that  $$p^2 \in \mathbb{Z} \Rightarrow q^2/3 \in \mathbb{Z} \Rightarrow 3|q$$  However, I'm not sure how to show that 3 divides p.    Edit:  Moron left a comment below in which I was prompted to apply the solution to this question as a proof of $\sqrt{3}$'s irrationality. Here's what I came up with...  [incorrect solution...]  ...is this correct?  Edit:  The correct solution is provided in the comments below by Bill Dubuque. iPhone Storage Space Inaccuracy (No Storage Space) When should I use "a" vs "an"? In the following example, is it appropriate to use a or an as the indefinite article, and why?     He ate __ green apple.   I know that in the case of just "apple", it would be "an apple," but I've heard conflicting answers for "green apple," where the noun is separated from the article by an adjective.  Also, which is more appropriate in this case:     He ate  __ enormous Pop-Tart. Clearing Flag Bits By Writing 1 What is the fastest way to create a 90° joint? I often want to create joints like this:    Since I end up making these more than a little, I'd like a fast way to do it (i.e. on the order of &lt; 10 seconds)  I've found a couple tools which come close to being the ideal solution, but I've had some problems with them as listed below:   When using the spin tool I usually end up having to fiddle with the location for a while in order to to get a natural curve:    Are there any techniques to expedite this process of fiddling? The bridge tool is nice because I can precisely specify where both ends of the joint will be, however I often end up with subtly uneven joints, probably due to my initial mesh being not quite square.    Is there a fast way to correctly line up the initial edge loops in a way that will result in an even joint? What features differ between the Xbox 360 and PC versions of Minecraft? What differences does the Xbox 360 version of Minecraft have compared to playing on the PC? To clarify - I'm concerned more about the differences exclusive to each platform, not just differences of features that will probably be added in future updates (for example, crafting). Otherwise, I feel this question could be compared to &quot;What is the difference between Minecraft version x and version y&quot;, which isn't what I'm asking. Please rate and comment. I want to improve; constructive criticism is highly appreciated. Please take style into account as well.  The following proof is solely based on vector space related axioms. Axiom names are italicised. They are defined in Wikipedia (see vector space article).  Vector spaces - Multiplying by zero scalar yields zero vector  \begin{array}{lrll} \text{Let} &amp; \dots &amp; \text{be} &amp; \dots \\ \hline &amp; F &amp;&amp; \text{a field.} \\ &amp; V &amp;&amp; \text{a vector space over $F$.} \\ &amp; 0 &amp;&amp; \text{an identity element of addition of $F$.} \\ &amp; \mathbf{0} &amp;&amp; \text{an identity element of addition of $V$.} \\ &amp; \mathbf{v} &amp;&amp; \text{an arbitrary vector in $V$.} \\ \end{array}  $$\text{Then, }0\mathbf{v} = \mathbf{0}.$$  Proof. We will denote by $1$ an identity element of scalar multiplication; we will denote by $(-\mathbf{v})$ an additive inverse of $\mathbf{v}$. \begin{align*} 0\mathbf{v} &amp;= 0\mathbf{v} + \mathbf{0}                     &amp;&amp; \text{by }\textit{Identity element of vector addition} \\ &amp;= 0\mathbf{v} + (\mathbf{v} + (-\mathbf{v}))   &amp;&amp; \text{by }\textit{Inverse elements of vector addition} \\ &amp;= (0\mathbf{v} + \mathbf{v}) + (-\mathbf{v})   &amp;&amp; \text{by }\textit{Associativity of vector addition} \\ &amp;= (0\mathbf{v} + 1\mathbf{v}) + (-\mathbf{v})  &amp;&amp; \text{by }\textit{Identity element of scalar multiplication} \\ &amp;= ((0 + 1)\mathbf{v}) + (-\mathbf{v})          &amp;&amp; \text{by }\textit{Distributivity of scalar multiplication (field addition)} \\ &amp;= ((1 + 0)\mathbf{v}) + (-\mathbf{v})          &amp;&amp; \text{by }\textit{Commutativity of field addition} \\ &amp;= (1\mathbf{v}) + (-\mathbf{v})                &amp;&amp; \text{by }\textit{Identity element of field addition} \\ &amp;= \mathbf{v} + (-\mathbf{v})                   &amp;&amp; \text{by }\textit{Identity element of scalar multiplication} \\ &amp;= \mathbf{0}                                   &amp;&amp; \text{by }\textit{Inverse elements of vector addition} \\ \end{align*} QED How do I draw ovals in TikZ? How can I draw this graph in the pic via tikz. I'm trying to determine the best way to truncate or drop extra decimal places in SQL without rounding.  For example:  declare @value decimal(18,2)  set @value = 123.456   This will automatically round @value to be 123.46, which is good in most cases.  However, for this project, I don't need that.  Is there a simple way to truncate the decimals I don't need?  I know I can use the left() function and convert back to a decimal.  Are there any other ways? Laptop (Asus x555u) screen turns off as soon as you remove the power cord Let $a,b,c\in \mathbb{Z}$. If $ac&gt;bc$ and $c&gt;0$, then $a&gt;b$   I think I would use contrapositive to prove this. But I am not sure proper contrapositive statement.   Is it If $a&lt;b$, then $ac&lt;bc$, and $c&lt;0$.? If so, contrapositive is not a good choice, isn't it? Lost my Downloads folder both from Dock and Finder I did something stupid apparently and lost my Downloads folder both from Dock and then when I opened Finder to drag it down to the Dock it somehow got deleted in the desktop.  Now although I can see the folder exists (e.g. by searching in Spotlight) I do not know how to restore it in the Dock and in Finder as well. Any help please? Rename all the files within a folder with prefix “Unix_” i.e. suppose a folder has two files a.txt and b.pdf than they both should be renamed from a single command to Unix_a.txt and Unix_b.pdf Prove by induction that $n! > n^2$ How does one prove by induction that  $n! &gt; n^2$  for $n \geq 4$ I am trying to override the menu.css file in the default Classy theme through my library file. I have read through the documentation, but anything I tried doesn't work.  What would be the correct markup to override or disable this file? Should I follow what was mentioned in the “duration of stay” or in the "validity of the visa"? I'm from Tunisia and I got a Schengen visa from the Austrian Embassy for  28 days, the “duration of stay”, and the number of entries is 1. But the validity of the visa is from 02/08/2015 to 13/09/2015.  Do I have to stay only 28 days, for example from 02/08/2015 to 29/08/2015 or can I stay there until 12/09/2015 ?  And if I have got to stay only 28 days, then can I choose the days of stay, that's mean can I stay in Austria for example from 09/08/2015 to 05/09/2015? Commutator of two normal subgroups with trivial intersections So I tried looking everywhere but I'm really lost with this proof. I need to to show that:  Let $H$, $K$ be normal subgroups of a group $G$, satisfying $H\cap K = \{e\}$. Let $h\in H$, $k \in K$. (a) Prove that the commutator $w = hkh^{-1}k^{−1}$ satisfies $w \in H$ and $w \in K$. Then conclude that $w = e$ (b) Prove that $hk = kh$, for all $h \in H$, $k \in K$. I see ads to other SE sites regularly on the sidebar of SO. Are these questions chosen by hand, or algorithmically? The reason I ask is that there was an ad pointing to  on Seasoned Advice. I'm all for a good laugh I suppose, but is this the kind of question that should be highlighted?  It's obviously a thriving community, but if this were my first exposure to that community, and I saw that the highest-rated answer -- from the user with the highest reputation -- was (and I paraphrase only lightly):  &quot;Why yes, there is tool that can cut cherry tomatoes in half.  It's fantastic for the job.  It's called a freakin' KNIFE!&quot;  would I ever want to visit again, let alone ask a question over there? First impressions count for a lot, and that one missed the mark IMHO. If the selection method is algorithmic, I suppose there's no reliable way to detect sarcasm in a highly-rated answer, but if it's manual, weeeellllllllll ... :)