how to find the source where the spam is originating from
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Taylor expansion for $\arcsin^2{x}$ I stumbled upon this particular expansion that was included in  post.    $$ \displaystyle \arcsin^{2}(x) = \frac{1}{2} \sum_{n=1}^{\infty} \frac{1}{n^{2} \binom{2n}{n}} (2x)^{2n}$$    This caught my eye because I remember trying to derive a Taylor series for $\arcsin^{2}(x)$ a while ago without much success.  Can anyone prove this or point me to a material that would show a proof of this identity?  EDIT :  Feel free to use any mathematical apparatus at hand. I'm not interested in a proof fit for a certain level, nor am I looking for utmost elegance (though that would be lovely). Get Currently Executing Class/Method Name? I have seen a few different flavors of exception logging utility out there, and a common concept is to capture the class and method that were running when the exception was thrown. In the case that made me wonder this, the logger is used for more than just exceptions. It has method signatures like:  public static void logMessage     (LoggingLevel loggingLevel, String className, String methodName, String message)   It seems to me that we should be able to get the className and methodName parameters programatically. Can it be done? How? Which is faster in Python: x**.5 or math.sqrt(x)? I've been wondering this for some time. As the title say, which is faster, the actual function or simply raising to the half power?  UPDATE  This is not a matter of premature optimization. This is simply a question of how the underlying code actually works. What is the theory of how Python code works?  I sent Guido van Rossum an email cause I really wanted to know the differences in these methods.  My email:     There are at least 3 ways to do a square root in Python: math.sqrt, the   '**' operator and pow(x,.5).  I'm just curious as to the differences in   the implementation of each of these.  When it comes to efficiency which   is better?   His response:     pow and ** are equivalent; math.sqrt doesn't work for complex numbers,   and links to the C  sqrt() function. As to which one is   faster, I have no idea... How do I fill an area with faces lined up in a grid over a not flat surface? Hello to everyone again,  I'm looking for an addon or a short cut to fill fast and simmetrically a NOT FLAT surface that needs to be closed with vertices. Doing it manually it takes a lot of time. I tried to do CTRL F and then Grid fill,but it didn't work. Neither F key works. Check the attached screenshot. thanks. I have installed Ubuntu 15.10 alongside Windows 10 with UEFI. To install Ubuntu, I chose the option install alongside Windows 10 or something similar to this. Then I created a new partition for Ubuntu and installed it. After installation, the boot menu did not show up. Initially I thought Ubuntu has not been installed, but when I plugged in the USB drive and wanted to install Ubuntu I saw an option of reinstalling Ubuntu on my machine. So, I found out that Ubuntu is installed. Pressing F8 and F12 also does not help. Can anyone help me bring up the GRUB boot menu? In Windows, I also entered the command bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi in cmd, but still the boot menu does not show up.  Reply (Himanshu) : Just boot in bios and, if you can, add boot option with name say ubuntu and path EFI/ubuntu/shimx64.efi. No need for live PCB or anything. Move the boot option to top. This is for dell GUI bios but I assume it works for all. Or you may want to see  or , where you can enable Windows Boot Loader for one boot or forever as you wish, and boot Ubuntu from it. If you want now, you can use the installed Ubuntu terminal to use the commands update-grub to use GRUB instead. (Not enough reputation to answer properly btw.) Connectedness in the Quotient Space Process substitution and pipe Is it possible to delete the "useless" apps pre-installed on my Mac? What is a “protected” or "highly active" question? Questions can be protected (i.e. marked "highly active").   What does it mean for a question to be protected? Why are some questions protected? Who can protect and unprotect questions? Who can answer a protected question? How are protected questions displayed? When should I protect or unprotect a question? When does the Community user protect a question? The word "quad" generally means 4. Quadratics don't have 4 of anything. Can anyone explain where the name comes from? Often when I mistype a command such as ls (e.g. I hit ENTER before I type 's') there is a long (~2s) delay after the terminal displays:  bash: l: command not found...   I can understand the reasons for a similar delay after an incorrect password is entered, per . But why delay after an unrecognized command? Does FAIL_DELAY in /etc/login.defs affect this also? In attempting to wrap my mind around the basic vocabulary, concepts, and methods of philosophy, I find myself wondering what the difference is between a philosopher and a theologian.   can have two meanings: 1. Theology is a rational study of the existence of God/gods and the nature of religious ideas. 2. Theology is simply a study of a particular religion (or all religions), really more the practice than the theory, but maybe a mixture.  It seems from an immediate reading that definition 1 would lead to the conclusion that a theologian is a philosopher (perhaps that theology is a branch or subset of philosophy), but definition 2 appears to be rather unphilosophical in nature.    So, how does philosophy answer this question?   Is theology considered a proper subset/branch of philosophy overall? Does it depend entirely on which of the above 2 definitions of theology fits a particular theologian as to whether he is a philosopher or not?   I think this answer is simple and fairly self-evident, but somewhere in my gut I feel like I'm missing something.  Is there a treatment of this question in the literature?    Edit: the answers so far seem to want to redefine theology or other terms - that is fine, but please be clear that you are redfining them, and provide, if possible, sources for why the term should be different than given (support from historical works, other sites, etc.). What does this symbol mean? (looks like a 1 with double vertical line) I'm studying a course on probability and statistics and at some point this symbol comes up without introduction. It looks like the number one, but slightly bigger and with a double vertical line.  First time it comes up is when discussing stochastic/random variables that are neither continuous nor discreet in an example:   And somewhat later in a proof:    Anyone got an idea what this symbol represents?  EDIT: Thanks for the fast answers, I was still editing the question for better (larger) images :) Create UEFI bootable USB stick to install Windows AND Ubuntu from it I know how to make a UEFI bootable stick to install Ubuntu (explained ) and I know how to make one to install Windows 7 (, sorry). I guess for Win 8 the procedure would be similar, but I haven't looked into it.  I also know how to make a legacy bootable stick from which I can install Windows and Ubuntu using YUMI. I have failed so far though at creating a UEFI bootable stick that can do this. When I do a UEFI boot from my YUMI multiboot stick it gives me no option to choose between Ubuntu and Windows (hardly surprising I guess) and instead simply UEFI boots Windows (which I find kind of surprising to be honest but maybe this is due to the fact that I added the Windows image after the Ubuntu image and this simply replaced Ubuntu's EFI boot files).  So how would I proceed to create such a bootable stick? Calculate difference between two dates (number of days)? Improving your own suggested edit makes you leave the First Posts review queue When reviewing the First Posts (and Late Answers) review queue, after you suggest an edit, you're back in the review queue and the I'm Done button is activated. So far, so good, but when I realize I want to edit something else as well (I often forget the tags), I can click the 'edit' link again. When I'm done improving my suggested edit, I'm suddenly outside the review queue.    This does not happen if you have enough reputation (2k) to edit posts straight away; then you always stay in the review queue. Odd behavor with POSIXct/POSIXlt and subsecond accuracy Why does a translation matrix need extra row? OpenSSL and error in reading openssl.conf file On Cesàro convergence: If $ x_n \to x $ then $ z_n = \frac{x_1 + \dots +x_n}{n} \to x $