Can't run OpenGL on Haskell
Can't get Freeglut to work with Haskell on Windows
Proving that $\sum\limits_{n = 0}^{2013} a_n z^n \neq 0$ if $a_0 > a_1 > \dots > a_{2013} > 0$ and $|z| \leq 1$ I'm going to teach a preparation course for the complex analysis qualifying exam from my university (which basically consists of me doing some problems from past exams) and I'm trying to solve some questions from previous exams. One of the questions is the following:           Prove that $\displaystyle{\sum_{n = 0}^{2013} a_n z^n \neq 0}$ if the coefficients  satisfy $a_0 &gt; a_1 &gt; \dots &gt; a_{2013} &gt; 0$ and $|z| \leq 1$.      I tried to approach the problem by using the reverse triangle inequality to try to isolate the leading term, which I thought should be the constant coefficient, as follows:  \begin{array} . \left|  \sum_{n = 0}^{2013} a_n z^n \right| &amp;= \left| a_0 +  \sum_{n = 1}^{2013} a_n z^n \right| \\ &amp;\geq |a_0| - \left|  \sum_{n = 1}^{2013} a_n z^n \right|\\ &amp;\geq |a_0| -  \sum_{n = 1}^{2013} |a_n z^n|\\ &amp;\geq a_0 -  \sum_{n = 1}^{2013} a_n |z^n|\\ &amp;\geq a_0 -  \sum_{n = 1}^{2013} a_0 |z^n|\\ &amp;= a_0\left( 1  -  \sum_{n = 1}^{2013} |z^n| \right) \end{array}  Then for $|z| &lt; 1$, we have that this last expression is equal to  $$ a_0\left( 1  -  |z| \frac{|z|^{2013} - 1}{|z| - 1} \right) $$  and my hope was to prove that this was always positive, nevertheless, after failing to prove it, I plotted the expression inside the parenthesis as a function of $|z|$, and found out that it changes sign in the interval $(0, 1)$.  Question  Can my approach somehow be made to work? And if not, how can I prove that the sum $\displaystyle{\sum_{n = 0}^{2013} a_n z^n \neq 0}$ under the given conditions?  Thank you very much for any help. I am using  to show the branch name in gnome terminal (Ubuntu 15.10) when working in a git repository. Based on the above I now have the below in my ~/.bashrc file:  # uncomment for a colored prompt, if the terminal has the capability; turned # off by default to not distract the user: the focus in a terminal window # should be on the output of commands, not on the prompt #force_color_prompt=yes    ...  # Add git branch if its present to PS1 parse_git_branch() {  git branch 2&gt; /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/(\1)/' } if [ "$color_prompt" = yes ]; then  PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[01;31m\]$(parse_git_branch)\[\033[00m\]\$ ' else  PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w$(parse_git_branch)\$ ' fi unset color_prompt force_color_prompt   As a result I now get:    so it works. But why has the coloring of my user@host been removed? And I would also expect that the branch name should be colored. Before it looked like this:    UPDATE: I have now tried this guide instead:    adding this to .bashrc:  parse_git_branch() {      git branch 2&gt; /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/' } export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ "   and that works:    Notice in .bashrc I also have this (default):  # uncomment for a colored prompt, if the terminal has the capability; turned # off by default to not distract the user: the focus in a terminal window # should be on the output of commands, not on the prompt #force_color_prompt=yes   I have yet to find the reason why that snippet gives the correct result and the other version does not. Any input on this?  Here is the version of my .bashrc that has the old snippet enabled that does not work: Is there anything like “cubic formula”? in elisp's let, how do you reference a variable bound in the same let while binding another variable? Consolidate tag wiki excerpt and body contents with regards to suggested edits At the moment, in major part because they are two separate post objects in the system, the excerpt and the body of a tag wiki count as two separate posts with regards to suggested edits in the queue. Mechanically, this is sane, but when it comes to handling the actual queue, it can be confusing. A body edit might consist of little more than a bed of links, which looks bad. But then an excerpt is shown that includes the rest of the data, and since excerpts can be included on the actual wiki page, it makes a lot more sense when they're taken in the same space.  And this is how they are composed, too. The actual edit interface for working on tag wikis has both the excerpt and the body on the same page. In a sense, the excerpt behaves a lot like the "title" of the wiki, if we make a parallel to normal post edits.  Thus, my suggestion (which is to say a suggestion that I repossessed from Robert Cartaino) is that when suggested edits are reviewed for tag wikis, that they be presented in a single unit, treating the excerpt the same as how a title is treated in a question edit. This way, relevant information that is crossed between the two isn't lost because they are reviewed separately. How do I parse command line arguments in Bash? Say, I have a script that gets called with this line: ./myscript -vfd ./foo/bar/someFile -o /fizz/someOtherFile  or this one: ./myscript -v -f -d -o /fizz/someOtherFile ./foo/bar/someFile   What's the accepted way of parsing this such that in each case (or some combination of the two) $v, $f, and  $d will all be set to true and $outFile will be equal to /fizz/someOtherFile? Use a baseline including all observations in lm() In linear regression, each predicted value is assumed to have been picked from a normal distribution of possible values. See below.  But why is each predicted value assumed to have come from a normal distribution? How does linear regression use this assumption? What if possible values are not normally distributed? Why are my quotation marks causing an “unexpected token” error with this command? I just reinstalled my Ubuntu system with 11.10, but ran into a problem when I tried to install Gimp 2.7.  I always get unmet dependencies (it's german, so I can't tell you the exact english translation):     Needs gimp-data (&lt;= 2.6.11-z) but 2.7.3-2011082002~oo should be installed   I already read the follow post, but the answers didn't really help me.  When I type in     sudo apt-get install gimp=2.6   it just says that there is no version 2.6 found. I get the same with 2.7.  I really need Gimp. But installing Gimp 2.6 isn't possible as well.  When I remove the repos for 2.7, I still get the same error. What is the 'molecular' origin of the viscosity? The molecular origin of elasticity is almost clear for me: at the very bottom the 'elasticity' comes from the attraction and repulsion between atoms when they are reasonably far from each other or very close (like Lennard-Jones potential). Is there a similar description for the viscosity as well? Where does it come from? Is there a way to set an "Adventure Mode Boundary" in Minecraft? Is there a way to set an "Adventure Mode Boundary" in Minecraft?  I am trying to create this village where players can spawn in, and then set out to explore the world and build and do normal minecraft stuff. I don't want them to destroy this village, so I want them to be in adventure mode when they are in the village and then switch them to survival when they leave, and vice-versa. When they return to the village, they get switched back to adventure mode.  In other words, I want to set an "Adventure Mode Boundary" to protect buildings. I am working without mods. I am hoping there is an simple way using command blocks. How to rename multiple files by removing the extension? How do I get the CPU temperature? How do I get the CPU temperature? Why does `last` show '{' and '|' in the TTY field? The advantages and disadvantages of using Kaiser Rule to select the number of principal components Is the Kaiser rule (choosing only PCs with eigenvalues >1, ) a reasonable method to select the number of principal components to retain? What are its pros and cons? Quotient of a local regular ring How can I prove this:     Let $A$ be a local regular ring with maximal ideal $\mathfrak m$ and $x \in \mathfrak m-\mathfrak m^2$. Then $A/(x)$ is a regular ring. Prove also that if $x\in\mathfrak m^2$, $x\ne 0$, the result does not hold anymore.   I don't know how to begin! Thanks to everyone who helps!  But if $d=\infty$? Please help me to find elements $a,b$ in a ring $R$ such that $a\mid b$ and $b\mid a$, but there does not exist any unit $u$ in $R$ such that $a=ub$. Do I need a transit visa for a layover via airports in the UAE, such as Dubai International Airport or Abu Dhabi International Airport? If so, what are the requirements for such a visa? Can I get the transit visa on arrival? Sync +- 70 000 records from CSV into drupal I have a CSV file with approx. 70.000 records that I want to import into Drupal 7. Once this is done the client will provide a new CSV file on a daily base that has to sync the updated rows to Drupal.   I wrote a import with  and the  module, but in both cases it takes like forever to import the 70.000 rows. Is there any other solution to import the data faster in Drupal 7?