CSS :after pseudo element not showing up on ?
CSS :after not adding content to certain elements
Evaluate the limit      $$ \lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n} $$   My Attempt:  $$ \lim_{n\rightarrow \infty}\left(\frac{n+1}{n}\right)^{n^2}\cdot \frac{1}{e^n} = \lim_{n\rightarrow \infty}\left(1+\frac{1}{n}\right)^{n^2}\cdot \frac{1}{e^n} $$  How can I solve the problem from this point? Is it ethical to use a textbook required for a class that was easily found online? As you can see in the picture, I have 13 out of 5. But it's been like this for about two months! What's the reason for that? how to get rid of arm64 in apt W: Invalid 'Date' entry in Release file /var/lib/apt/lists/_var_cuda-repo-8-0-local_Release N: Skipping acquire of configured file 'non-free/binary-arm64/Packages' as repository 'http://repository.spotify.com stable InRelease' doesn't support architecture 'arm64' E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Some index files failed to download. They have been ignored, or old ones used instead.   After I installed Jetpack for Jetson tx1, my ubuntu constantly tries to fetch arm updates. Is there a way to disable this?  EDIT:   $dpkg --print-architecture amd64  $dpkg --print-foreign-architectures i386 arm64   I see that arm64 is included in foreign architectures. How do I remove it? What is wrong with my date regex? Changing default width of blocks in beamer How to solve the "io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information" error on Minecraft? I am getting the following error when I try to connect to a Minecraft server:  This is all servers, not just one. The error says:  io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: Version 1.12  I've tried:  Restarting Minecraft Restarting Computer Uninstalling and Reinstalling Mincraft Uninstalling and Reinstalling Java Altering Firewall Restarting Internet I've messed with my port, made a second windows account, reset netsh winsock Checked hosts Made a new WINDOWS account  The overlay in the bottom right is Geforce's Overlay for game capturing. I don't have any mods installed. A Mojang support ticket wouldn't help. Im desperate. Why do some lenses focus past infinity? On the kit 18-55 lens that came with my Nikon D5100 I have noticed that when trying to focus on infinity for shots in dark conditions (star-trails, etc) the lens tends to move past infinity out of focus and need to be brought back a little to get a clear infinity focus point.  Is there a good trick for getting a clear infinity focus when in pitch dark conditions? Is there a term for a foreign word that looks like an English word but has a completely different meaning? examples:         Gift (German) = poison   poisson (French) = fish   embarazada (Spanish) = pregnant   sauce (Spanish) = willow   triviale (Italian) = vulgar   parentes (Portuguese) = relatives   slim (Dutch) = smart What is the best way to increase my reputation and privileges? I'm not sure if this is a stupid question, but here goes anyway... I have only recently started learning PHP and Javascript and I'm reasonably proficient. One of the reasons I'm so proficient is because I LOVE Stack Overflow and find most of the solutions to my dilemmas here.   But I've found that I never get the chance to ask a question because it has normally been asked many times before and when I go through the unanswered questions to try and help someone else, they are generally WAY over my head.  So I'm not sure how to get more privileges. I can't even vote up answers that I like or that helped me. I can't comment to thank someone for their solution. It is most tragic and demoralising... How do I change the situation? Are there other explanations for slow tyre pressure loss? I rode my road bike on Friday and the tyres were at the correct pressure then, around 100psi.  On Tuesday, I jumped on without checking them and quickly realised something was wrong with the rear tyre.  It wasn't completely flat but was fairly soft.  I hadn't gone far so went home and took the car to work instead.  When I got home later, I was surprised to find the tyre, while still soft, hadn't lost all pressure by any means.  It was around 40psi and felt the same as when I left it in the morning.  I decided there must be a slow leak somewhere, but I couldn't find one anywhere, putting the inner under water and going around it methodically looking for bubbles.  I've never failed to find a leak before that way.  I've switched it out anyway because I don't want to mess around with my commute, but I'm curious ... is there another explanation for that amount of pressure loss?  Or must there have been a puncture somewhere that I missed somehow?  The tyres (whole bike) are pretty new and in excellent condition. Prove that $\sum_{k=1}^{n}k\binom{n}{k}=n\cdot2^{n-1}$ I want to prove the following: $$\sum_{k=1}^{n}k\binom{n}{k}=n\cdot2^{n-1}$$ what I did is(use binominal): $$\binom{n}{k}X^k\cdot 1^{n-k} = (X+1)^n$$ $$k\binom{n}{k}X^k\cdot 1^{n-k} = k(X+1)^k-1$$ now I replace $k$ by $n$ and insert $X=1$ , I will get now $n\cdot2^{n-1}$ what you are suggesting? there is another way to do that? thanks! Order of nested random effects in lme4 I just fit a model in lme4, and I'm wondering what the heck I fit...  I have individuals id, and each is measured pass/fail on items that can be described using two factors, f1 and f2. My theory says that id and f2 can interact. So I want to compare these models:  # f2 doesn't matter m1 &lt;- lmer(pass ~ f1 + (1|id), family="binomial")  # f2 is a fixed effect, doesn't interact with individuals m2 &lt;- lmer(pass ~ f1 + f2 + (1|id), family="binomial")  # f2 is a nested random effect, interacting with individuals m3 &lt;- lmer(pass ~ f1 + (1|f2/id), family="binomial")   First, am I right that there's a random effect of each level of f2, and each individual's level of f2 is partially pooled, depending on the number of observations for that individual?  Second, does it make sense to fit f2 as a fixed effect with random individuals nested within each level of f2? How does one write that?  Third, what's this, with f2 and id reversed in the formula? I typed it by accident, but now I want to understand it.  m3weird &lt;- lmer(pass ~ f1 + (1|id/f2), family="binomial") Can you reject a postdoc offer after the PI has paid a large sum for flights/accommodation for your visit? I am being considered for a very nice industry scientist position but this involves many interviews and assessments and can take some time.  However I have also accepted an invitation to the US (I'm in Australia) to give a presentation in relation to high likelihood of employment as a postdoc in a research institute.  The postdoc supervisor has arranged for sightseeing and lab visits and hotels. I feel bad if somehow I wish to pursue the industry position.  Has anyone had a similar experience and have you turned down something like that before? Random quadratic equation I would like to produce quadratic equation with integer coefficients.  Here's my code using pgfmath.  \documentclass{article} \usepackage{tikz} \pgfmathsetseed{\pdfuniformdeviate 10000000}  \begin{document} $\pgfmathdeclarerandomlist{signe}{{+}{-}}% \pgfmathrandomitem{\s}{signe}% \pgfmathparse{random(2)}% \pgfmathparse{ifthenelse(\pgfmathresult==1,"-"," ")}\pgfmathresult \pgfmathrandominteger{\a}{1}{6} \pgfmathparse{ifthenelse(\a==1," x^{2} ","\a x^{2}")}\pgfmathresult % coeff a \pgfmathdeclarerandomlist{lincoeff}{{}{2}{3}{4}{5}{6}} \pgfmathrandomitem{\b}{lincoeff}% \pgfmathrandomitem{\s'}{signe}% \pgfmathsetmacro{\e}{random(0,6)} \pgfmathparse{ifthenelse(\e==0," ", " \s' \b x ")}\pgfmathresult % coeff b \pgfmathrandominteger{\c}{0}{6} \pgfmathrandomitem{\s''}{signe}% \pgfmathparse{ifthenelse(\c==0,"","\s'' \c")}\pgfmathresult % coeff c =0$ \end{document}   It works but it seems to be not a good way, I had some pain with the x-coeficient and my solution looks complicated. I tried to use an ifthenelse inside an other ifthenelse but without success. Is there a better way ? Do lure modules and incense cause new pokemon to spawn near you, or existing pokemon to be drawn to you? Does it mean that two threads can't change the underlying data simultaneously? Or does it mean that the given code segment will run with predictable results when multiple threads are executing that code segment? I used an SRTM DEM to create a hillshade in QGIS 2.2.0. However, the resultant hillshade seems to be vertically exaggerated. Also, changing the settings for scale and z-factor does not have any effect on the resultant hillshade. I have tried both options in QGIS, Analysis-> DEM (Terrain models) and Terrain analysis -> Hillshade. Both methods gave the same results.  Is this an isolated incident, a bug, or am I missing something? What does functools.wraps do? In a comment on this , someone said that they weren't sure what functools.wraps was doing. So, I'm asking this question so that there will be a record of it on StackOverflow for future reference: what does functools.wraps do, exactly? An elementary proof of $\int_{0}^{1}\frac{\arctan x}{\sqrt{x(1-x^2)}}\,dx = \frac{1}{32}\sqrt{2\pi}\,\Gamma\left(\tfrac{1}{4}\right)^2$