How to run a subprocess in the background python
How to start a background process in Python?
Find all solutions of the equality $y^2=x^3+23$ for integers $x,y$   I guess, that x cannot be even. because we can apply mod 4 test  say $x=2k$ then $y^2=8k^3+23\equiv3\mod(4)$   but, this is not possible, since the square of an integer is congruent to $0$ or $1$ $\mod (4)$  so $x$ is of the form $4k+3$ or $4k+1$  $x=4k+3$ is also not possible for the same reason but for the last case the test fails.  any hints ? Who can see what in my profile? When editing my user profile (name, date of birth, etc.), how can I tell which information can be seen by other users (publicly visible) and what is only used by the system (and how it's used)? How to test if a string is basically an integer in quotes using Ruby I'm using an unsigned repo in Ubuntu 16.04 from Debian multimedia:  deb http://www.deb-multimedia.org jessie main   To install deb-multimedia-keyring, I'm running:  apt-get update &amp;&amp; apt-get install deb-multimedia-keyring -y   This gives an error:  W: GPG error: http://www.deb-multimedia.org jessie InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5C808C2B65558117 E: The repository 'http://www.deb-multimedia.org jessie InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. Finding out the area of a triangle if the coordinates of the three vertices are given What is the simplest way to find out the area of a triangle if the coordinates of the three vertices are given in $x$-$y$ plane?   One approach is to find the length of each side from the coordinates given and then apply . Is this the best way possible?   Is it possible to compare the area of triangles with their coordinates provided without actually calculating side lengths? Are PDO prepared statements sufficient to prevent SQL injection? Do creatures that enter the battlefield at the same time see each other enter? How to use my aliases in my crontab? How should I apply brick to an interior wall? Can it happen that the image of a functor is not a category? On Hilton and Stammbach's homological algebra book, end of chap. 2, they wrote in general $F(\mathfrak{C})$ is not a category at all in general. But I don't quite get it. I checked the axioms of a category for the image, and I think they are all satisfied. Am I missing something? Thanks. Should I add a 'Home' Button to the navigation? I know that it is common behavior to have the logo of a web page be a link to the home page, but should I also have a 'home' link in the navigation bar for it as well? Let $(x_n)_{n=1}^{\infty}$ be a sequence such that $|x_{n+1} - x_n| &lt; r^n$ for all $n \geq 1$, for some $0 &lt; r &lt; 1$. Prove that $(x_n)_{n=1}^{\infty}$ is a Cauchy sequence.  I understand that a Cauchy sequence means that for all $\varepsilon &gt; 0$ $\exists N$ so that for $n,m \ge N$ we have $|a_m - a_n| \le \varepsilon$. But this one is really giving me a headache.  I tried doing something like: let $ m &gt; n$. Therefore $x_n - x_m$ =  $(x_n - x_{n-1}) + (x_{n-1} - x_{n-2}) + ... + (x_{m+1} - x_m) $ and then somehow using the triangle inequality to compute some sum such that $x_n - x_m$  &lt; sum which would be epsilon?  any help is appreciated, thank you. How can I use docker without sudo? On Docker's documentation pages, all example commands are shown without sudo, like this one:  docker ps   On Ubuntu, the binary is called docker.io. It also does not work without sudo:  sudo docker.io ps   How can I configure Docker so that I don't need to prefix every Docker command with sudo? Get two letter country code in Apex method I want to write an Apex method that takes a country name as input and returns the equivalent two letter country code (ISO A2). Is there a way to write it without explicitly hard coding all countries and code in the method? Install Ubuntu on Intel Mac I've recently taken up a position in an all Mac workshop - We have Intel based Apple machines. Can I dual boot Ubuntu on my machine, if so how? Prove $3(x^2y+y^2z+z^2x)(xy^2+yz^2+zx^2)\ge xyz(x+y+z)^3$ if $x,y,z$ are positive real numbers,Prove:$$3(x^2y+y^2z+z^2x)(xy^2+yz^2+zx^2)\ge xyz(x+y+z)^3$$ Additional info:$\sum_{cyc}$ denotes sums over cyclic permutations of the symbols $x,y,z$. I'm looking for solutions and hint that using Cauchy-Schwarz and AM-GM because I have background in them.  Things I have done: Writing Left hand side in expanded form:$$LHS=3(\sum_{cyc}x^3y^3+\sum_{cyc}xy^4z+3x^2y^2z^2)$$ Right now I don't have good idea were to start(Is expanding and looking for AM-GM is good?).So any hint is appreciated. Source : This inequality can be found as Problem 42, page 13, in the book &quot;Old and New inequalities&quot; by Titu Andreescu, where it is attributed to Manlio Marangelli. Xubuntu live usb persistence - how to? I'm using Xubuntu 13.04 from live usb.  I know that in order to be able to keep files/settings/etc after restart, USB live disk should be created with some storage reserved. However since I got this USB from a friend who created installation, I don't know if he reserved any space, and so my questions are:   How can I find out amount of space reserved (if any)? If no space is reserved, can I manually chose USB/HDD location to store my settings in order to be able to boot into them the next time I log on?   I'm currently running a very long session and it would help me if I could somehow be able to store my settings (firefox, apt-gets, xrandr screen conf. ... ) to not have to do it again after I reboot.  Thanks,  IR Superluminal neutrinos I was quite surprised to read this all over the news today:     Elusive, nearly massive subatomic particles called neutrinos appear to travel just faster than light, a team of physicists in Europe reports. If so, the observation would wreck Einstein's theory of special relativity, which demands that nothing can travel faster than light.   &mdash;  Apparently a CERN/Gran Sasso team measured a faster-than-light speed for neutrinos.   Is this even remotely possible? If so, would it be a real violation of Lorentz invariance or an "" effect?   The ; a webcast is/was planned .  News conference video Verification the integral identity $\int_0^\pi \ln(1+\alpha\cos(x))dx=\pi\ln\left(\frac{1+\sqrt{1-\alpha^2}}{2}\right)$. I have to verify that     $$\int_0^\pi \ln(1+\alpha\cos(x))dx=\pi\ln\left(\frac{1+\sqrt{1-\alpha^2}}{2}\right)$$   with $|\alpha|&lt;1$. It is my homework and don't know where to begin. A story about a male protagonist with special eyes that tells him if things are safe or not; green = safe. Can’t remember if it’s a manga or webtoon. It starts with a male protagonist who was dying on a battlefield, the goddess took pity on him, sent his emotions back into his younger self, (not memories). He had eyes that told him what is safe/good and what is dangerous/bad by using colors: green, orange, red. He used this to gamble, his eyes stopped working, borrowed money from his ex-girlfriend (who works in a cafe). Money got stolen while he took a nap by a river, the evil lady who stole his money tried to get him to enter a contract. From his future emotions, he knew he wanted an invitation instead. This leads to a gathering of people in a school gym, their tasks are given. Invited people are given bags with tools. An oni busted out under the floor. People get killed. Stairways with gates, etc. This is considered the tutorial. Points are given after, those points are needed to buy daily necessities. The protagonist had the highest points, given VIP room. Etc.