The "Esc" key in my bluetooth keyboard doesn't work, how to fix it?
Keyboard key stuck or not being recognized; how to fix
Data Recovery - How to Restore Deleted / Formatted Files on HD Micro SD Card Background:    I put in a friend's SD Card to format it because it was having problems. Then I put mine back in and I think my phone formatted my SD Card. I had a ton of pictures on there that are now gone! I put the card into the computer and there's only 2mb of cache files on there and none of the original directories.   I already tried the following freeware recovery applications:         Neither of them were able to retrieve any files. Undelete took 1minute to scan for files and came up with 0 files.  Recuva took 10 minutes for their "deep scan" which doesn't seem thorough enough at all for this 8GB SD Card. I need something that's a lot more heavy duty.  I don't mind paying for an application to get the data back if necessary...   Questions:     Which application can I use to recover my deleted picture files from my 8GB HD Micro SD Card?   Why did Anroid format my SD card?   How can I tell if it's a phone problem, data problem, or SD Card problem? How to sort a ConcurrentSkipListMap by value? I get different lightning render with the same scene camera setup.  Cycles render (both experimental and supported feature set) gets weaker lightning and needs more energy.  How can I get the same lightning and reflection setup with EEVEE and Cycles? What is the difference between a symbolic link and a hard link? Recently I was asked this during a job interview. I was honest and said I knew how a symbolic link behaves and how to create one, but do not understand the use of a hard link and how it differs from a symbolic one. Declare a const array Interference between strokeopacity and fillopacity I have a few circles in a drawing, and want to highlight some of them.  \begin{tikzpicture}  \coordinate (A1) at (0,0); \coordinate (A2) at (1,0); \coordinate (A3) at (1,1); \coordinate (B)  at (1,0);  \draw (A1) -- (A2); \draw (A1) -- (A3); \draw (B)  -- (A3);  \foreach \point in {A1,A2,A3,B} {    \fill [black,draw=white](\point) circle (3pt); }  \pgfsetstrokeopacity{.3} \pgfsetfillopacity{.3} \fill [red,draw,rounded corners,line width=9pt] (A1) -- (A2) -- (A3) -- cycle; \pgfsetstrokeopacity{1} \pgfsetfillopacity{1} \end{tikzpicture}   I would like the whole area surrounding the A points to be of the same color, but the strokeopaticy and the fillopacity interfere.  Is there some ay I can prevent this?  Note: in my actuall use scenario, there are too many coordinates for manual adjusting to be an option (otherwise I would just do with a fill with rounded corners, with points calculated manually). Prove $e^{x+y}=e^{x}e^{y}$ by using Exponential Series docky crashes from time to time for me. How can I make it restart automatically after it crashed? What is a good set of naming conventions to use when developing on the Force.com platform? I've looked in the Apex developer's guide and a saw the   which has basically only has this:   We recommend following Java standards for naming, that is, classes start with a capital letter, methods start with a lowercase verb, and variable names should be meaningful.   I'm looking for something more in depth, such as end all Controllers with Controller and their tests with ControllerTest, etc.  What is a good set of naming conventions to use when developing on the Force.com platofrm?  It would be preferable if the answer has something that handles custom objects, classes, visualforce pages, and components and not just Apex classes. Derivation of E step in EM algorithm While im going through the derivation of E step in EM algorithm for pLSA, i came across the following derivation . Could anyone explain me how the following step is derived.   $\sum_z q(z) log \frac{P(X|z,\theta)P(z|\theta)}{q(z)}  = \sum_z q(z) log \frac{P(z|X,\theta)P(X,\theta)}{q(z)} $ proving topological equivalence How would I show that $$d_E = \sqrt{\sum_{i=1}^n(x_i-y_i)^2}$$ and $$d_\infty= \sum_{i=1}^n|x_i-y_i|$$ and $$\sup\{|x_1-y_1|,|x_2-y_2|,...,|x_n-y_n|\}$$ are topologically equivalent on $\mathbb{R}^n$? I can do it for $\mathbb{R}^2$, but I'm not sure how a generalization looks like. The product of a normal and Rademacher variables, independent from each other Let $X\sim N(0,1)$ and let $Z$ be a random variable independent of $X$ such that:  \begin{equation} \Pr(Z=z) = \begin{cases} \frac{1}{2} &amp; \mbox{if $z = -1$ or $z=1$}, \\ \\ 0 &amp; \mbox{otherwise}. \end{cases} \end{equation}   Define $Y = ZX$. Show that $Y \sim N(0,1)$. Determine $\operatorname{Cor}(X,Y)$. Are $X$ and $Y$ independent?   Progress:  I'm basically stuck at the beginning. I got as far as $P(ZX &lt; y) = P(Z &lt; y/X)$, which I'm not even sure is correct. I'm also not clear on what it means by defining $Y = ZX$ - does it mean I need to state the probability density function or something? And how do I show that $Y \sim N(0,1)$? Why did Littlefinger give Sansa to the Boltons? This question is about the TV show only.  In the books, Sansa is still with Littlefinger and everything that happens between Sansa and Ramsay in the show actually takes place between Ramsay and Jeyne Poole in the books.  However I don't recall why Littlefinger sends Sansa north. Apparently, in the books, it's safer to keep her traveling. So why did he do it in the show? As we all know that Kurama's chakra is of the healing nature type. This is known from many mentions about it in the wiki page of .  My question is, what is the nature type of the chakra of the other Tailed beasts?  Note: This is my thinking why there should have been a nature type to each of the tailed beasts.   As we all know that when Rikudō Sennin was about to die, he split his powers among his two sons (the older son inherited his powerful chakra and spiritual energy, and the younger son inherited his powerful life force and physical energy). Similarly, when creating the nine tailed beasts from the Shinju, he must have split the chakra based on their nature so that each tailed beast had a unique natured chakra.  Any insight on this would be very much welcomed. The direct sum $\oplus$ versus the cartesian product $\times$ In the case of abelian groups, I have been treating these two set operations as more or less indistinguishable. In early mathematics courses, one normally defines $A^n := A\times A\times\ldots\times A$; however in, for example, the fundamental theorem of finitely generated abelian groups, we normally write that every such group is isomorphic to one of the form $$ \mathbb{Z}^n \oplus \mathbb{Z}_{r_1} \oplus \cdots \oplus \mathbb{Z}_{r_t}  $$ where $\mathbb{Z}^n$ now means $\mathbb{Z}\oplus\mathbb{Z}\oplus\cdots\oplus\mathbb{Z}$.  From an intuition perspective, and in the sense of sets, is this more or less the same as $\mathbb{Z}\times\mathbb{Z}\times\cdots\times\mathbb{Z}$? (Bear in mind I am normally using these ideas in relation to homology groups.) How does the Mac choose which connection to use when both Wifi and Ethernet are connected? When I'm connected to two networks with separate routers using Wifi and Ethernet, how does my Mac know what connection to use when I visit a website? When should I use "shall" versus "will"? Which is the correct use of these two words, and in which context should one be used rather than the other? I just got off a very long and very frustrating phone call with Apple support.  I purchased a used Apple computer which came installed with Mountain Lion. Meaning that the computer was shipped by Apple with Mountain Lion installed, and received by me with that same installation.  As a precaution, I tried to reinstall Mountain Lion via Recovery mode. This failed because my Apple ID hasn't purchased Mountain Lion.  Apple insisted that because I didn't purchase the computer new, I don't have a license for OS X. I don't believe this is correct, or even legal. This means that anyone using a used computer is doing so illegally, unless they've purchased a separate OS license.  Am I way off-base here? I'm pretty sure I now "own" a copy of Mountain Lion, and Apple is in the wrong. If this is correct, what are my options? How do I find the files installed by a particular package? Where is the .deb file to look at? I have installed pulseaudio-module-bluetooth using apt.  $ type pulseaudio-module-bluetooth bash: type: pulseaudio-module-bluetooth: not found $ which pulseaudio-module-bluetooth $ whereis pulseaudio-module-bluetooth pulseaudio-module-bluetooth:   Clearly, I'm looking for the wrong thing.  The package does not simply install a command that is the same name as the package.  Alright, then.  I want to find out what all commands (or executables) this package installed, and their locations.  The answers to "" tell me how to find the files installed by the package if I have a .deb file.  I'm not installing directly from a .deb file, though.  I'm using apt.  Where is the .deb file that that used?  Is there a copy on my system somewhere that I can query with the commands in the answers to that question?  Where?  If there isn't a local copy on my system, can I get one with apt?  How?  Is there some handy apt (or similar) command that wraps this up for me, so that I do not have to run dpkg-deb directly?  What is it?  Can I find the package's file list entirely on-line, without explicitly downloading any .deb files and before installing anything with apt?  How? If $A$ is compact, is then $f(A)$ compact?