Why wont this equation split using \begin{align} and \end{align}
Aligning equations within multline
While browsing I have received notification on Google "Unusual traffic from your computer network"   We're sorry..."your computer or network may be sending automated queries. To protect our users, we can't process your request right now." See Google Help for more information.  Right now I am using the "Ubuntu 12.04" 32 bit version.  Any suggestion, why this is happens &amp; How it resolve?  Thank you for your worthy suggestion. Some days ago I realized that  (as well as ) never throw an IOException when writing, flushing or closing.  Instead it sets an internal flag (trouble=true) when an error occurs. It's not possible to get the exact exception, but only if there was some exception ().  My question is: why would one want to have such behavior? Isn't that bad API design? How to format a disk/sdcard as FAT32 in windows 10 Badges with long names overflow on the profile page Intuition on the Kullback–Leibler (KL) Divergence I have learned about the intuition behind the KL Divergence as how much a model distribution function differs from the theoretical/true distribution of the data. The source I am reading goes on to say that the intuitive understanding of 'distance' between these two distributions is helpful, but should not be taken literally because for two distributions $P$ and $Q$, the KL Divergence is not symmetric in $P$ and $Q$.   I am not sure how to understand the last statement, or is this where the intuition of 'distance' breaks down?   I would appreciate a simple, but insightful example. Using modulo operation to draw graph I'm trying to prove the problem below - which comes from Munkres' "Analysis on Manifolds" book in the section on the Inverse function theorem.  Since its in the chapter on the Inverse Function Theorem I figured I'd start by showing that $f$ satisfies the conditions of the theorem.  Writing the Jacobian shows that it's both $C^r$ and we get $\det f'(x,y)=4x^2+4y^2\neq0$ when $x&gt;0$.  So we can apply the theorem but I'm unsure of how to proceed to show that $f$ is $1$-$1$.  And I didn't see how to use the hint they provided.  Thanks!      Let $f\colon \mathbf R^2\to \mathbf R^2$ be defined by the equation   $$f(x,y)=(x^2-y^2,2xy).$$   (a) Show that $f$ is one-to-one on the set of all $(x,y)$ with $x&gt;0$. [Hint: If $f(x,y)=f(a,b)$, then $\|f(x,y)\|=\|f(a,b)\|$.] I saw a video of Johann Cruyff , isn't that against the rules? A post here on DBA.StackExchange () has spawned an interesting question (at least, interesting to me) regarding performance in MySQL.  The context is that we want to insert a record in a table for each row that is updated.  Before the row is updated, we want to store off a previous value and then increment one of the columns (a "version" column).  If we do this inside a trigger, it works out nicely.  For MySQL, the triggers are , so it would be an easy solution.  Select the data currently in the table, insert it into the logging table, and the update the "version" column in the new data.  However, it's possible to move this logic to a stored procedure. If you do that, you're performing the insert, then incrementing the "version" column in the table.  The entire thing would be set based.   So, when it comes to performing this insert, would this be more performant to use the set-based stored procedure approach or a trigger based approach?  This question is for MySQL (since it has row-by-row triggers), although it could apply to other row-by-row trigger DBMSs. Choosing between meaningful and meaningless hostnames When is a review task "completed" or "invalidated"? In my game, XP needed to reach the next level is Current Level × Level Threshold.  Given that, how can I get my current level from the total XP ever earned?    For example:  Level Threshold = 50 Current Level = 1   Starting at level 1, I would need (1 × 50) = 50 XP to get to level 2, and so on.  Level 1: 50 XP needed to reach level 2 Level 2: 100 more XP needed to reach level 3 Level 3: 150 more XP needed to reach level 4   In other words, the progression table is as follows:  Level 1: 0 XP to 49 XP Level 2: 50 XP to 149 XP  Level 3: 150 XP to 299 XP Level 4: 300 XP to 499 XP   If I have 300 XP, I'll just reached level 4. How can I calculate that generally? Foreign key constraint on array member? Invalid group name: Group names must begin with a word character I received the following exception when I was using the Regex class with the regular expression: (?'named a'asdf)  System.ArgumentException: parsing \"(?'named a'asdf)\" - Invalid group name: Group names must begin with a word character.   What is the problem with my regular expression? How can I prevent system clipboard image data being pasted into a WPF RichTextBox Geometry with Trigonometry What are some good introductions to philosophy? I've been searching the questions posed here, and don't seem to find one that gives the answers I am looking for. I've proposed to start a  on meta but no one proposed anything, so I feel I must ask this question: What are some books generally regarded as good for a general introduction on philosophy? By this I mean good books that can introduce you to philosophy in general and throughout the times, not to some philosophy or period in particular.   almost answers mine, except for the fact that most things proposed there are not books, thus not giving me much options to weigh upon.  regards contemporary philosophy in particular. And  has the same problem as the first one, plus the fact that it asks for layman's terms, which is not what I am looking for.  I've been tempted to buy Will Durant's , but am not sure if it is the best book to get started on philosophy (plus, the book has some mixed reviews). I also checked , which seems to be unanimously good, but has the format of dictionary/encyclopaedia, which is not exactly what I am looking for (at least as a main source).  also seems to be a good introduction regarding how to do philosophy, rather than to its history and ideals (this also interests me, but I'd rather learn about the philosophers and their theories first).   It is also important to point out that I have little notions (or none at all) on philosophy. I would like to read something that covers from classical to contemporary philosophy generally (although I do not know if there is such a book), so that from there I could pick some author, period or branch of philosophy in particular to read further on. So, to sum up, I would like to 'hear' your opinions on what are some books generally regarded as good for a general introduction on philosophy. I just got an Android tablet and when I try to install an app on the Play store it says:      error retrieving information from server [RPC:S-3].   I've tried clearing the data for the Play Store app &amp; turning it off &amp; back on but it didn't work. Why aliases in a non-interactive Bash shell do not work Enable replace image feature in LibreOffice