What is the easiest way to reset a configuration file that I accidentally deleted?
How can I restore configuration files?
In my textbook, a relationship is plotted between the resistance of the material and the temperature, and the temperature coefficient is defined as the slope of that graph divided by an arbitrary resistance $R_1$ on the graph. Does that mean that the coefficient varies depending on the temperature I choose to divide the slope by?  If so, how does it stand as a valid reference to the material’s resistance growth rate with temperature?  If not, then where did I go wrong with this train of thought? I'm looking for a short story whose title I can't remember.  In it a wealthy man practices cloning and consciousness transfer to achieve immortality, often parading older bodies around his estate naked (not a nice guy). The story follows a final transplant, which doesn't go as expected. The man is left trapped with his memories and no ability to speak, while the clone walks off behaving exactly as he would. Reprojecting LiDAR data with libLAS, error: "latitude or longitude exceeded limits"? Abstract class with all concrete methods Can anyone help me with this limit problem without L'Hopital rule and Taylor series? $$\lim_{x\rightarrow\ -\infty}\left(-2\frac{\arctan(x)}{\pi}\right)^x$$ Definable real numbers Show that if $a \equiv b \pmod n$, $\gcd(a,n)=\gcd(b,n)$ My problem is how to somehow relate the the gcd and congruence. I know that $(a,b) = ax + by$. I also know that $a \equiv b \pmod n$ means $n\mid a-b$. Any hints?  Thanks! Windows XP INSTALL BSOD Recently I got a virus on my computer that completely wiped the hdd. I am trying to install windows xp to this: DV7-636bus laptop from HP, and I get the following BSOD:  A problem...............and Then Select Safe Mode.  Technical Information:  ***STOP: 0x0000007E (0xC0000005,0xF73B9D66,0xF78D1EA0,0xF78D1B9C)  acpi.sys - Address F72B9D66 base at F73AE000, Datestamp 480252b1   Does any one know of a solution for this? Determine $4$ specific digits in $34!$ Terminal only shows up as a black window Can we actually discourage downvotes? Before you disagree with me with a downvote, or just want to be funny, please hear me out. From the :  The upvote privilege comes first because that's what you should focus on: pushing great content to the top. Downvoting should be reserved for extreme cases. It's not meant as a substitute for communication and editing.  I have honestly never seen a downvote reserved for an extreme case. The process is usually 1) downvote post if it's bad and don't comment. (Not much of a process, is it?) As you stay on the site longer and longer, you develop a carelessness towards downvotes (as I have), but for new users, it's really discouraging.  question inspired me to [ask balpha to] make , which is a list of users with 1 rep who have the  badge. That's the closest I could get to new users who deleted their own posts after downvotes came in. Don't get me wrong, I know the argument about being nice to new users very well, but I still believe it to be an issue. And since , users are much more inclined to go the lazy route and downvote bad questions. No alternative measures (see below) are taken, for the most part. Personally, I leave a comment and don't downvote until the asker shows no interest in fixing their post. The only other measure taken to discourage downvotes (on answers) is the -1 rep punishment to the downvoter, which is absolutely meaningless and inconsequential anyways. How are we supposed to educate new users when we don't teach them what to do, don't direct them to the FAQ, and discourage them with downvotes right off the bat?  Instead of voting down: If the post is spammy or offensive — flag it. If the question is duplicate or off-topic — flag it for moderator attention. If something is wrong, please leave a comment or edit the post to correct it.  We claim to discourage downvoting, yet I see answers like  that encourage us to downvote first and ask questions later when a question is simply unclear or effortless. It's just an awful chain reaction. A new user comes to the site asking a question, but that doesn't work out too well, so they get downvotes, delete the question in shame, and don't get the help they deserve as a fellow writer of code and programmer. Strip away the quality of the site for a moment: the core functionality of this site, and the only reason I and a lot of other users are (still) on it, is to receive and give help to/from others. I enjoy making sure fellow programmers get the answer they need, because this site has helped me get mine when I needed them. Quality can still be maintained if content is fixed rather than downvoted more often. So can we stop discouraging new users from continuing to use this site and actually start to discourage downvoting? I think we need to encourage effort towards teaching and helping new users understand the system and why their post is bad rather than slapping them in the face with downvotes that they don't know how to interpret anyways. I'm leaving ways we can do this up to others. My first thought was to increase the punishment for downvoting answers and to no longer make question downvotes free, but those wouldn't be well-received, judging by the history of similar suggestions. . Refused UK Visit visa for lack of sufficient funds - What more can I do? Do an action and its Euler-Lagrange equations have the same symmetries? Assume a certain action $S$ with certain symmetries, from which according to the Lagrangian formalism, the equations of motion (EOM) of the system are the corresponding Euler-Lagrange equations.  Can it happen that the equations of motion derived by this procedure have different kinds and/or numbers of symmetries than the action one has started with? And if yes, are there underlying principles that state why which kind of symmetries the action does not have can emerge in corresponding EOMs or which kind of symmetries of the action can potentially disappear in the EOMs derived from the Euler-Lagrange equations? Is it possible to perform a complete reinstall on an Android smartphone? I occasionally perform such a reinstall on my Windows PC. I repartition my hard drive, format the partitions, and then install Windows on a blank partition. Can this be done on an Android smartphone? (I have an unlocked Sony Xperia S.) Increasing extent of Raster? Hot and Week tabs not shown to non-logged in users (except on SO) I am trying to proof the following algorithm to see if a there exists a path from u to v in a graph G = (V,E).   Reach := {u} LastCardinality := 0 while LastCardinality &lt; |Reach| do   LastCardinality := |Reach|   Next := null   foreach i &lt;- Reach do     foreach j &lt;- V do       if(i,j) exists in E then         Next := Next + {j}   Reach := Reach + Next return Reach   So far I have got that the output needs to be Reach = Goal where Goal = {r | r exists V, there is a path from u to r}. I also have three invariants that I am pretty sure will help prove this.   Reach is always a subset of Goal and Next is always a subset of Goal. After an arbitrary K times through the while loop, for every t that exsits in V, if t has a path of length k+1 from u, then t exists in Reach If Reach is a subset of Goal before the while loop then LastCardinality &lt; |Reach|   I know that to finish up the proof, I need to prove termination, the invariants, and correctness but I have no idea how. I think I need to use induction on the while loop but I am not exactly sure how.   How do I proof those three characteristics about an algorithm? I am trying to mimic our institute's PPt-template for presentation foils using the beamer-class. The corporate quidelines prescribe the use of Helvetica as the main font. However, package helvet does not provide a good mathematical font. Therefore I want to replace it with the math font from the cmbright package:  \documentclass{beamer}  \usepackage{lmodern} \usepackage[T1]{fontenc}  %main font Helevtica \renewcommand{\familydefault}{\sfdefault} \usepackage{helvet}  %prevent beamer from meddling with math fonts \usefonttheme{professionalfonts}  %following lines borrowed from cmbright.sty \DeclareSymbolFont      {operators} {OT1}{cmbr}{m}{n} \DeclareSymbolFont        {letters} {OML}{cmbrm}{m}{it} \SetSymbolFont      {letters}{bold} {OML}{cmbrm}{b}{it} \DeclareSymbolFont        {symbols} {OMS}{cmbrs}{m}{n} \DeclareMathAlphabet{\mathit} {OT1}{cmbr}{m}{sl} \DeclareMathAlphabet{\mathbf} {OT1}{cmbr}{bx}{n} \DeclareMathAlphabet{\mathtt} {OT1}{cmtl}{m}{n} \DeclareMathAlphabet{\mathbold}{OML}{cmbrm}{b}{it} \DeclareMathSymbol{\alpha}{\mathalpha}{letters}{11} \DeclareMathSymbol{\beta}{\mathalpha}{letters}{12} \DeclareMathSymbol{\gamma}{\mathalpha}{letters}{13} \DeclareMathSymbol{\delta}{\mathalpha}{letters}{14} \DeclareMathSymbol{\epsilon}{\mathalpha}{letters}{15} \DeclareMathSymbol{\zeta}{\mathalpha}{letters}{16} \DeclareMathSymbol{\eta}{\mathalpha}{letters}{17} \DeclareMathSymbol{\theta}{\mathalpha}{letters}{18} \DeclareMathSymbol{\iota}{\mathalpha}{letters}{19} \DeclareMathSymbol{\kappa}{\mathalpha}{letters}{20} \DeclareMathSymbol{\lambda}{\mathalpha}{letters}{21} \DeclareMathSymbol{\mu}{\mathalpha}{letters}{22} \DeclareMathSymbol{\nu}{\mathalpha}{letters}{23} \DeclareMathSymbol{\xi}{\mathalpha}{letters}{24} \DeclareMathSymbol{\pi}{\mathalpha}{letters}{25} \DeclareMathSymbol{\rho}{\mathalpha}{letters}{26} \DeclareMathSymbol{\sigma}{\mathalpha}{letters}{27} \DeclareMathSymbol{\tau}{\mathalpha}{letters}{28} \DeclareMathSymbol{\upsilon}{\mathalpha}{letters}{29} \DeclareMathSymbol{\phi}{\mathalpha}{letters}{30} \DeclareMathSymbol{\chi}{\mathalpha}{letters}{31} \DeclareMathSymbol{\psi}{\mathalpha}{letters}{32} \DeclareMathSymbol{\omega}{\mathalpha}{letters}{33} \DeclareMathSymbol{\varepsilon}{\mathalpha}{letters}{34} \DeclareMathSymbol{\vartheta}{\mathalpha}{letters}{35} \DeclareMathSymbol{\varpi}{\mathalpha}{letters}{36} \DeclareMathSymbol{\varrho}{\mathalpha}{letters}{37} \DeclareMathSymbol{\varsigma}{\mathalpha}{letters}{38} \DeclareMathSymbol{\varphi}{\mathalpha}{letters}{39} \let\upDelta\Delta \let\upOmega\Omega \let\upGamma\Gamma \let\upTheta\Theta \let\upLambda\Lambda \let\upXi\Xi \let\upPi\Pi \let\upSigma\Sigma \let\upUpsilon\Upsilon \let\upPhi\Phi \let\upPsi\Psi  %doesn't seem to have an effect %\DeclareMathSizes{12}{12.5}{10}{10}  \begin{document} \begin{frame}  Some Math E$E$ \end{frame} \end{document}   This works quite well, except that the math letters are somewhat smaller than the normal Helvetica text. Is there a way to scale the fontsize, say by 1.1, if the typesetter is in math mode? How to automatically resize the vertical bar in a set comprehension? I have a simple command which I use to write set comprehensions so that the braces automatically resize with respect to size of the enclosed arguments, e.g.  \usepackage{amsmath} \newcommand{\set}[1]{\left\lbrace #1\right\rbrace}  \begin{equation*} \set{x \in X \mid x &gt; \frac{1}{2}}   \end{equation*} % Produces something like: { x : X | x &gt; 1/2 }   However, the \mid vertical bar wont resize like the braces { .. } do. How can I get the \mid to resize as well? Variance of the future value of a cash flow I want to compute the variance of $FV =A\sum_{k=1}^n(1+r)^k=:g(r)$, assuming interest rate $r\sim\mathrm{N}(\mu,\sigma^2)$ and constant equal payments $A$. As discussed in the comments, the Delta Method gives an approximation $\mathrm{Var}[FV]≈\sigma^2\times(g′(\mu))^2$. Is there a way to get an exact answer?