Can we stop 'experienced' SE users from marking questions as duplicate on their own?
Someone flagged my question as already answered, but it's not
Handling registration ID changes in Google Cloud Messaging on Android Find all entire functions such that $|f(z)|\leq |\sin(z)|$ for all $z\in\mathbb C$. Height and minimal number of generators of an ideal How can I determine the height and the least number of generators of the ideal $ I=(xz-y^2,x^3-yz,z^2-x^2y) \subset K[x,y,z] $?      I tried to calculate the dimension of the vector space $I/I\mathfrak m$ with $\mathfrak m=(x,y,z)$, but I'm not able to find it.  I think the height is $2$, because the affine variety should be a curve, and also I know that the ideal is prime, so I need a chain $0\subset \mathfrak p \subset I$. Maybe $(xz-y^2)?$ Is it prime? $P_n(x):=1+ \sum_{m=1}^n\dfrac{x^m}{m!}$ has no real root for even $n$ and exactly one real root for odd $n$ Is there any way to hide your Steam status from others? Is there any way to prevent others from seeing your Steam status without removing them as a friend?   Let's say I want to play Borderlands 2 without letting some friends know. Is there any way to hide my status to prevent them from knowing I'm playing it?  Basically, what I'm asking if Steam has an "Appear Offline" option. Why are there $736$ matrices $M\in \mathcal M_2(\mathbb{Z}_{26})$ for which it holds that $M=M^{-1}$? I'm currently trying to introduce myself to cryptography.  I'm reading about the Hill Cipher currently in the book Applied Abstract Algebra. The Hill Cipher uses an invertible matrix $M$ for encryption and the inverse matrix $M^{-1}$ for decryption. The book recommends to use a matrix $M$ for which it holds that $M=M^{-1}$, since we then have the same key for encryption and decryption.  In the book, they use a $2 \times 2$ matrix $M$ over $\mathbb{Z}_{26}$ as example, and state that for there are 736 $2 \times 2$ matrices for which it hold that $M=M^{-1}$.  I'm trying to pick up on as much as possible when reading things, since I find it counter-productive for learning to skip something, when you don't get the theory behind it. Can someone enlighten to me, as to why it is that there are 736 possible $2 \times 2$ $M=M^{-1}$ matrices and how to find them? Particular nodes are missing from node editor I am looking for the  but it is not available under the Vector nodes menu or any other menu. I have Blender 2.77 which cooresponds with the manual version in the above link.    I also cannot find the Texture Coordinate or Gradient Texture.  Likely I am doing something wrong. How to add a guest account without a password? Is there a way to format a UTC time into any arbitrary string format I want in java?  Basically I was thinking of having some class take the timestamp and I pass it is string telling it how I want it formated, and it returns the formatted string for me.  Is there a way to do this? Submitting a form by pressing enter without a submit button Well I am trying to submit a form by pressing enter but not displaying a submit button. I don't want to get into JavaScript if possible since I want everything to work on all browsers (the only JS way I know is with events).  Right now the form looks like this:  &lt;form name="loginBox" target="#here" method="post"&gt;     &lt;input name="username" type="text" /&gt;&lt;br /&gt;     &lt;input name="password" type="password" /&gt;     &lt;input type="submit" style="height: 0px; width: 0px; border: none; padding: 0px;" hidefocus="true" /&gt; &lt;/form&gt;   Which works pretty well. The submit button works when the user presses enter, and the button doesn't show in Firefox, IE, Safari, Opera and Chrome. However, I still don't like the solution since it is hard to know whether it will work on all platforms with all browsers.  Can anyone suggest a better method? Or is this about as good as it gets? Animated movie that had black robots that turned people into stone late 1960s to 1970s It was a weird sci-fi animated movie I saw only a little bit of it. This is what I recall:   It was old but had color, so I assume it was late 1960s to early 1970s. The animation and style reminded me of  but it wasn't as psychedelic. The setting was an alien planet with all sorts of bizarre creatures. The tech was advanced but not a dominant aspect of the planet's culture. The people lived simple and peaceful. The protagonist is a man with bluish skin like the others. The antagonists were humanoid shaped black robots that shot a beam that would turn people into stone. I find myself repeating a lot of:  mkdir longtitleproject cd longtitleproject   Is there a way of doing it in one line without repeating the directory name? I'm on bash here. NSdate Assuming wrong time zone What is the equation for the tension on the ends of a cable suspended at different heights? I'm looking for an equation to find the tension on the ends of a cable suspended between two poles (one higher than the other) with no load but the cable itself.    I determined that the tension would be different on each end, that the shape of the suspended cable would be a  truncated at one end, and that the following would be the variables necessary in the equation:   cable weight cable length vertical distance between ends horizontal distance between ends   Some links that could be helpful: It seems that most people who use the ignored tags feature end up with a fairly long list of those tags.  Although , it is sometimes necessary to add new ignored tags manually (typically when adding some-tag*).  It would be a lot easier if the add box was above the long list of ignored tags rather than below. I suppose the same would apply to the favorites tags for consistency's sake. Explain why $E(X) = \int_0^\infty (1-F_X (t)) \, dt$ for every nonnegative random variable $X$ How do you compute negative numbers to fractional powers? Why is the de-facto standard sigmoid function, $\frac{1}{1+e^{-x}}$, so popular in (non-deep) neural-networks and logistic regression?   Why don't we use many of the other derivable functions, with faster computation time or slower decay (so vanishing gradient occurs less). Few examples are . One of my favorites with slow decay and fast calculation is $\frac{x}{1+|x|}$.  EDIT  The question is different to  as I'm only interested in the 'why' and only for the sigmoid. Inconsistent line spacing How to make a bootable windows USB in Kali Linux