I am a linux newbie so this maybe a very stupid question, I will try to ask my question by giving an example. When I execute command in terminal  chromium-browser  chromium opens up but I cannot close the terminal without closing the browser. when I quit the terminal browser closes automatically So I wanted  know how to close that terminal without closing the browser.
I opened Cairo-dock in my terminal with: open cairo-dock and that worked but if I close the terminal it goes with it. How can I keep it open regardless of the terminal?
Showing that a map is bijective and finding its inverse Let $S$ := {$(x, y) ∈ \mathbb R^2: x^2 + y^2 = 1$} be the unit circle. Let $p = (0, -1)$ ∈ $S$. Define a map $F$ from $\mathbb R$ × {$0$} to $S$ as follows: Given $(t, 0)$, let $F((t, 0)) = (x, y)$ ∈ $S$ be the intersection of $S$ with the line through $p$ and $(t, 0)$. Derive a formula for $F$. Show that $t$ → $F((t, 0))$ is a bijective map from $\mathbb R$ to $S$ \ {$p$}, and also derive a formula for its inverse.  If we express $S$ in polar coordinates: $$S:=\{(r,\varphi):r=1,\varphi∈(-\frac\pi{2},\frac{3\pi}{2})\}$$ then, from simple trigonometric relations, the inverse function $\Phi$ is: $$\Phi(\varphi)=\tan\frac{\frac\pi2-\varphi}2$$ and its inverse $F$ is: $$F(t)=\frac\pi{2}-2\arctan t$$ After changing coordinates back to cartesian, $F$ will look like: $$F(t)=(\cos(\frac\pi{2}-2\arctan t),\sin(\frac\pi{2}-2\arctan t))$$ which can be further simplified to: $$F(t)=(\frac{2 t}{t^2 + 1},\frac{1 - t^2}{t^2 + 1})$$ Is this the formula of $F$? Is it correct? And I know that to show that $\phi$ : $\mathbb R$ →  $S$ \ {$p$} is a bijective map, I have to show that $\phi$ is injective and surjective. But how do I do that? Can someone please help me show that $\phi$ is bijective? and how can I derive a formula for its inverse? How to import a module given its name as string? I'm writing a Python application that takes as a command as an argument, for example:  $ python myapp.py command1   I want the application to be extensible, that is, to be able to add new modules that implement new commands without having to change the main application source. The tree looks something like:  myapp/     __init__.py     commands/         __init__.py         command1.py         command2.py     foo.py     bar.py   So I want the application to find the available command modules at runtime and execute the appropriate one.  Python defines an __import__ function, which takes a string for a module name:     __import__(name, globals=None, locals=None, fromlist=(), level=0)      The function imports the module name, potentially using the given globals and locals to determine how to interpret the name in a package context. The fromlist gives the names of objects or submodules that should be imported from the module given by name.       Source:    So currently I have something like:  command = sys.argv[1] try:     command_module = __import__("myapp.commands.%s" % command, fromlist=["myapp.commands"]) except ImportError:     # Display error message  command_module.run()   This works just fine, I'm just wondering if there is possibly a more idiomatic way to accomplish what we are doing with this code.  Note that I specifically don't want to get in to using eggs or extension points. This is not an open-source project and I don't expect there to be "plugins". The point is to simplify the main application code and remove the need to modify it each time a new command module is added. Proving replacement theorem? I want to see if I am understanding the proof of the replacement theorem correctly.   Let $V$ be a vector space that is spanned by a set $G$ containing $n$ vectors.  Let $L \subseteq V$ be a linearly independent subset containing $m$ vectors.  Then $m\leq n$ and there exists a subset H of G containing exactly $n-m$ vectors s.t. $L \cup H$ generates $V$.   The proof in the book says to start with $m=0$. In that case $L=\varnothing$, the empty set.        Let's assume this theorem is true for some integer $m \geq 0$.   Let $L = \{v_j\}_{j=1}^{m+1}$ and define it as a linearly independent subset of $V$ consisting of $m+1$ vectors.  Since any subset of a linearly independent set is linearly independent as well ($S_1 \subseteq S_2 \subseteq V$), then $\{v_j\}_{j=1}^m$ is linearly independent also.   It then says to use the induction hypothesis to say that $m \geq n$. Well, ok, but that seems sort of pulled out of nowhere to me. The next step is to say that there is therefore another subset, $\{u_k\}_{k=1}^{n-m}$ of G such that $\{v_j\}_{j=1}^m \cup \{u_k\}_{k=1}^{n-m}$ spans $V$.   That being the case there are scalars $(a_j)_{j=1}^m$ and $(b_k)_{k=1}^{n-m}$ which you can multiply by the vectors $v_j$ and $u_k$. You can then add the two sets of vectors, yielding $$\sum_{j=1}^m a_j v_j + \sum_{k=1}^{n-m} b_k u_k = v_{m+1}$$  At this point I am not sure I understand things. Because we are assuming $n-m&gt;0$ -- otherwise $v_{m+1}$ is linearly dependent. But then it says not only is $n&gt;m $ but $n&gt;m+1$, and that is where I am losing the plot to get to the next step. How to prove that a simple graph having 11 or more vertices or its complement is not planar? Calculate the limit including binomial coefficients $\lim\limits_{n\to\infty}{\sum\limits_{k=n}^{5n}{k-1 \choose n-1}(\frac{1}{5})^{n}(\frac{4}{5})^{k-n}}$  It's clear that we can simplify the limit a little bit, after which we get:  $\lim\limits_{n\to\infty}{(\frac{1}{4})^{n}\sum\limits_{k=n}^{5n}{k-1 \choose n-1}(\frac{4}{5})^{k}}$  I could further simplify the expression, but I feel like there's a more elegant solution.   Give me a hint, please Is it safe to disable System Integrity Protection? While using OS X El Capitan 10.11.x, is it safe to disable System Integrity Protection? There are all these additional apps that modify folders and the dock that I want to install but you have to disable rootless first.  Good idea or bad idea? Is the Macbook 12 inch's USB-C charger interchangeable with other USB-C chargers or devices? If there is only the Macbook 12 inch USB-C charger nearby, can it be used to charge other USB-C devices, such as any Android phones that also use USB-C? (will it be "too powerful" and damage other devices?)  Vice versa, if there is a Quick Charge 2.0 or 3.0 USB-C charger from other devices nearby, can it be used to charge the Macbook 12 inch?  The main concern is about whether it could damage the device or battery. I am a newbie in Latex. My goal is to have the word "Chapter" in the title of any chapter, and the word "Appendix" in the title of appendix. I also want to add "Appendix" in TOC. However, using the following MWE from my university, I end up having "Appendix A" in TOC. How can I remove the letter "A" in TOC.  \documentclass[12]{thesis}  \RequirePackage{tocloft} \RequirePackage{titlesec} \usepackage[titletoc]{appendix}  \newcommand{\spacemultiplier}{1.5} \renewcommand{\baselinestretch}{\spacemultiplier}\normalsize  \renewcommand{\frontmatter}{ %TABLE OF CONTENTS \addcontentsline{toc}{chapter}{Contents} {\renewcommand{\baselinestretch}{1}\normalsize \tableofcontents } \newpage \titleformat{\chapter}[display]{\renewcommand{\baselinestretch}{1.5}\LARGE\sc\fillast}{Chapter   \thechapter}{0pt}{}[\renewcommand{\baselinestretch}{\spacemultiplier}\normalsize] \titlespacing{\chapter}{0pt}{1.4cm}{20pt} \setcounter{chapter}{0} }  % Appendix setup \newcommand{\universityappendix}{ \appendix \titleformat{\chapter}[display]{\renewcommand{\baselinestretch}{1.5}\normalsize \LARGE\sc\fillast}{Appendix}{0pt}{} \titlespacing{\chapter}{0pt}{-30pt}{20pt} \renewcommand{\baselinestretch}{1.5}\normalsize }   \begin{document}  \frontmatter  \chapter{blah blah} This is a chapter  \universityappendix \begin{appendices} \chapter{blah blah} this is appendix \end{appendices} \end{document}   Thanks I have a problem , i can't open synaptic >:(  root@dopeboy:~# synaptic No protocol specified ** (synaptic:6940): WARNING **: Could not open X display No protocol specified (synaptic:6940): Gtk-WARNING **: cannot open display: :1   I have try to Re-install it but is not working, any idea how to fix?! VPS Ubuntu 14.04 LTS. Change edit approval/rejection I accidentally clicked reject on the suggested edit on this question(). I can't find the button to change it to Approve? Show that a Cauchy sequence has a fast-Cauchy subsequence I would like to create an alias to rm command in order to have a confirmation message after executing this command. So I am creating an alias like this alias rm='rm -i'. But as far as I know this is a temporary alias and it lives until you close the terminal.  As it is explained  to save alias permanently I need to execute ~/.bash_aliases or ~/.bashrc commands in terminal and add my alias there. But when I execute ~/.bashrc I get following error message :  bash: /home/bakhtiyor/.bashrc: Permission denied   When I run ~/.bash_aliases I get another error message like this:  bash: /home/bakhtiyor/.bash_aliases: File or directory doesn't exist.   What is the actual problem and how can I solve it? How does one parse XML files? I have now enough reputation points on Stack Overflow to edit every post directly. But sometimes (especially if this is about a field where I'm not savvy, or when I try to edit a question title without having understood the question itself) I might be not totally sure about whether my edit really is an improvement.  For now, I have these options:   Do the edit anyway, hope that someone else will catch it if it is wrong Don't do the edit, and hope that someone else will see this post and edit it in the right way Let a comment and hope that someone will see it (either after editing or instead of it). Flag the post for moderator attention (but will the moderators know it better?) Search the right chat room to find someone who knows more about the topic.   All these are not really optimal, I think.  I would like to have a check box     [_] Submit this edit for approval   which, when checked, would submit the edit into the usual edit approval queue. Then I would get at least one or two other pairs of eyes looking over my edit, and maybe even improving it.  (I don't really care about the +2 reputation for the edit - I think it should be without any reputation difference here.)  There's an  for nearly giving everyone the ability to suggest edits that the post owner can approve, but I'm simply interested in being able to insert them into the general edit queue where anyone can approve them.  Actually, I could do this right now by having a low-reputation sock puppet (or a totally anonymous edit), but I think this is not the intended use for sock puppets, is it? Also, I would like to be able to get feedback for my edit. In Java is there a way to check the condition:  "Does this single character appear at all in string x"  without using a loop? Could it be a structure of "How many -singular noun- is there?" We had an argument in our collage if it's possible to have such structure:     "How many -singular noun- is there?"   For example:      How many chair is there?   The claim of the supporters: This structure should be used in case that t is not known whether there is one one or more chairs there. While just in case that it is known certainty that there are more than one chair, it should be "how many chairs are there".    The claim of the opponents: This structure cannot be since using the phrase "how many" always should be with a plural noun.  Both sides are not native English speakers, then I would like to know what is the truth. How do I check if someone accessed my computer? I need to check the list of files accessed in my computer (ex: yesterday on particular time). Is it possible?   Or   I need to check whether anybody accessed my computer (when I left it unlocked) or not for a particular time. error in python d not defined. How do I install openjdk 7 on Ubuntu 16.04 or higher? I would like to upgrade my main system to 16.04, but I work on projects that require OpenJDK 7.   Apparently it is not available from a trivial apt-get install openjdk-7-jdk. Only versions 8 and 9 are listed in the repository.  Can anyone point me to instructions on how to install it? This has happened to me many times in the last 5 years: an upgrade broke my system. Each time I end up with this situation, I have to reinstall the whole system, which is really annoying.  Is there any way to roll back the most recent upgrade to be able to have a functional system without reinstalling? If not, which is the best way to suggest this as a top priority idea?   I read this idea was described in brainstorm.ubuntu.com, but it feels it is dead... and the forums are full of examples of upgrades breaking things, that's why I feel something needs to be done about this topic. Thanks!