alias for date-stamping to create a directory(in .bashrc)
bashrc lazy substitution
Is 512 bits a more secure hashing than 256 bits? Importing only certain rows between spreadsheet documents Document 1 has many rows of data.  How do I import into document 2 only those rows that have a certain value in column C? How does one prove that if $n \mid (a^{n}-b^{n}) \ \Longrightarrow$ $ \displaystyle n \mid \frac{a^{n}-b^{n}}{a-b}$ where $a,b, n \in \mathbb{N}$.  What i thought of is to consider $$(a-b)^{n} \equiv a^{n} + (-1)^{n}b^{n} \ (\text{mod} \ n)$$ and if we suppose that $n$ is odd then we have, $$(a-b)^{n} \equiv a^{n} -b^{n} \ (\text{mod} \ n)$$ and since $n \mid (a^{n} - b^{n})$ we have $$(a-b)^{n} \equiv 0 \ (\text{mod} \ n) $$  I think i am far away from the conclusion of the problem, but this is what i could work on regarding the problem. A word for someone who you share a half-sibling with This is probably best explained with an example.  Alice and Bob have a child, Erin. Bob and Carol have a child, Frank. Carol and Dan have a child, Grace. Clearly, Erin and Frank are half-siblings, because of their father, Bob. Similarly, Grace and Frank share their mother, Carol.  Erin and Grace have no parents in common, and are thus not half-siblings. However, is there a term for their relation? Is there a direct, elementary proof of $n = \sum_{k|n} \phi(k)$? How to recover from a Nvidia fail on Ubuntu 16.04? I have an older Nvidia video card and my PC crashes when installing the driver for the video card in Ubuntu 16.04. When I get to the login screen but no further: after entering my password, the system went into a loop and returned always back to the login screen [with funny stripes present].   How do I fix this problem? Prove: $\lim\limits_{n \to \infty} \int_{0}^{\sqrt n}(1-\frac{x^2}{n})^ndx=\int_{0}^{\infty} e^{-x^2}dx$ I'd like your help with the following claim to prove:  $$\lim_{n \to \infty} \int_{0}^{\sqrt n}\left(1-\frac{x^2}{n}\right)^ndx=\int_{0}^{\infty} e^{-x^2}dx.$$  I think I should use the claim:     Let $a,b$ two real numbers and $\{f_n\}$ a sequence of continuous functions on $\left[a,b\right]$  which converges uniformly to $f$ on $[a,b]$. Then    $$\lim_{n\to\infty}\int_a^bf_n(t)dt=\int_a^bf(t)dt.$$   But for this, I must prove that $(1-\frac{x^2}{n})^n$ uniformly converges to $e^{-x^2}$.  How do I do that? One of the hardest and trickiest things to do is to prove this uniformly converges.. every function has its own way. I believe that the more examples I'll see the easiest it will be. Thanks again! Add asterisk after labels in enumerate I would like to add an asterisk after certain labels in the enumerate environment. So for example  \documentclass{article} \begin{document}  \begin{enumerate}     \item Kuttel     \item* Daddeldu \end{enumerate}  \end{document}   but without the space between 2. und *. Where can I find gedit's backup files and how to open them? So, I just finished off the first part of an important task for school and today when I was going to continue, the document with my notes were gone. The only fragment I've got left of my file is the back up file, which doesn't show in the folder where I saved the document, but I can search for it.  Is there anyway which allows me to open the back up file, save it as a text file and continue my task? I don't really have the time for running restoring tools, which never has helped me in a satisfactory way anyway.  I wrote the document in gedit and my version of Ubuntu is 12.10. Moving from SQL 2005 [SQL_Latin1_General_CP1_CI_AS] to 2008 - will I lose any features by using 'backwards compatibility' How to vertically center content with variable height within a div? I have an Asus Sabertooth Z170 motherboard, with a Samsung 950 Pro m.2 NVMe drive on it. I've heard in the past that installing Windows 7 on an NVMe drive was a significant amount of work. Its now August 2016, is it still difficult? I've seen updates from Microsoft saying they've added support for NVMe in Windows 7.  Can I just download Windows 7 from Microsoft () and put it on a USB drive and install?  Is it harder than that? Why my DCIM folder is empty seen in the computer but not empty in the phone I am using HuaWeiNova device, and I tried to access it with aft-mtp-cli. $ aft-mtp-cli $ ls DCIM/  I got folders listed here: |-photos |-Camera ....  When I tried to list or download my photos in the Camera/ folder, I got nothing. Only the empty folders are listed and the folders that contains files are not shown at all. I am quite sure my photos are stored in the Camera folder in my cell phone. How come I could not access my photos with my computer ? If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons? If photon energies are continuous and atomic energy levels are discrete, how can atoms absorb photons? The probability of a photon having just the right amount of energy for an atomic transition is $0$. External hard disk detection issue what exactly happened:  I have a Seagate 1 TB external hard disk.It was working fine till now.The problem started when I plugged it in my android phone and then back in my pc then simply it does not showup anywhere and :  It does not appear in file explorer   It does not appear in disk management   It is not listed in Diskpart command   It only appears in Device Manager under disk drives   It does not appear in BIOS  only makes sound when plugged and unplugged.  disk spins and light is also showing.   . What I already tried:   updated usb drivers.  used new cable also.  plugged in another pc  usb mass storage is also enabled in BIOS  no issue in any usb port  Anything else i can do? Take a screenshot of a webpage with JavaScript? Smooth rendering of bitmap fonts FM transmitter design? I stumbled across a relatively simple FM radio transmitter online.    Credit:   I wanted to understand how it works (it is called "super simple" on the website), but several hours I have nothing but a vague understanding.   I believe R2, L1, C3 form an oscillator, and then the transistor Q1 is used to modulate the signal. C1 would just be used to remove any DC offset. However, this leaves R1, C2, C4, C5, and R3 and,  for these components,  I have no clue what they do.   Could someone please explain how this "super simple" transmitter works? How much swap should I take for 1GB to 8TB of RAM on 14.04 or higher? I'm going to install 64 bit 14.04 on a new machine with something like 1 to maybe 128GB RAM and even more RAM later. How much space should I allocate to the swap partition?   And especially: WHY those recommendations for these numbers?    (None of the existing answers  and  explain any of the why and are a bit dated if we look at 1GB or RAM and up) Using shell's read command with live editing functionality (readline like) Is there a standard (POSIX) way of asking the user some data from within a shell script, with  for example, while allowing live edition of the text being typed (what readline does)?   I know bash has read -e varname that allows for the person launching the script to use keyboard arrows for exemple, to edit or correct what has just been typed without deleting the last entered characters with backspace.   However, read -e is . And still, it is pretty cumbersome to delete all that has been wrote if you realise you made a mistake at the beginning of your long sentence...