Restore deleted Mysql Directory in linux
Recovering accidentally deleted files
If two vectors $a$ and $b$ make angle $\alpha$ and $\beta$ with the $x$-axis, prove, using vectors, that:   $$\cos(\beta - \alpha) = \cos \alpha \cos\beta + \sin\alpha \sin\beta$$   I tried taking components of each vector along the plane, but that didn't get me anywhere. I tried taking component of vector $b$ along vector $a$, but I also got stuck there. Can anyone point me in the right direction? Prove that $\lim_{n\to\infty}a_n\le \lim_{n\to\infty}b_n$ Theorem  Let $\{a_n\}$ and $\{b_n\}$ be convergent real sequences. Assume that there exists a $N\in\mathbb{N}$ so  $a_n\le b_n$ (eq. 1)  for all $n\ge N$. Then  $\lim_{n\to\infty}a_n\le \lim_{n\to\infty}b_n$.  My attempt at proving  Let $a=\lim_{n\to\infty}a_n$ and $b=\lim_{n\to\infty}b_n$. $a$ and $b$ are real numbers because the limit of a sequence of real numbers is a real number (which is a corollary in my textbook). For proof by contradiction, assume  $b&lt;a$.  Let $\epsilon=\frac{a-b}{2}$. Then we can find $N_a,N_b\in\mathbb{N}$ so  $|a-a_n|\le\frac{\epsilon}{2}$ when $n\ge N_a$, (eq. 2)  $|b-b_n|\le\frac{\epsilon}{2}$ when $n\ge N_b$. (eq. 3)  In a textbook I found that I should do the following:  Choose a $n$ so $n\ge\max(N,N_a,N_b$), then eqs. (1-3) are satisfied. Then  $a-\epsilon\le a_n+\frac{\epsilon}{2}-\epsilon$  How do I get that last thing? Is it necessary to do a proof by contradiction or can one do a direct proof? I have a SQL Server instance that has a linked server to an Oracle server. There is a table on the Oracle server called PersonOptions which contains the following data:  ╔══════════╦══════════╗ ║ PersonID ║ OptionID ║ ╠══════════╬══════════╣ ║        1 ║ A        ║ ║        1 ║ B        ║ ║        2 ║ C        ║ ║        3 ║ B        ║ ║        4 ║ A        ║ ║        4 ║ C        ║ ╚══════════╩══════════╝   I need to pivot that data so the results are:  ╔══════════╦═════════╦══════════╦══════════╗ ║ PersonID ║ OptionA ║ Option B ║ Option C ║ ╠══════════╬═════════╬══════════╬══════════╣ ║        1 ║       1 ║        1 ║          ║ ║        2 ║         ║          ║        1 ║ ║        3 ║         ║        1 ║          ║ ║        4 ║       1 ║          ║        1 ║ ╚══════════╩═════════╩══════════╩══════════╝   Any suggestions? I am using Snow Leopard and Windows 7 with bootcamp. I would like to be able to save some files to my OSX partition from Windows. I would also like to have files (say, photos, source code, etc) that I can manage with both partitions. Is it possible to get the two partitions to "play nice"? New questions, Show Recommended, Sort Newest not working Under what condition we can interchange order of a limit and a summation? Nested sequence of non-empty compact subsets - intersection differs from empty set I have the following proposition:  "If $(S_n)$ is a sequence of compact subsets of a metric space such that  $S_1 \supseteq S_2 \supseteq ... \supseteq S_n$  Then $\bigcap^\infty_{i=1} S_i$ $\neq$ $\emptyset$"  My lecture notes provide the following proof, whose last step I don't understand:    Proof: Assume by way of contradiction that $\bigcap^\infty_{i=1} S_i$ = $\emptyset$. Let $V_n := (S_n)^c$ for each $n$. The class $\mathbb{C} :=\{V_n: n \in \mathbb{N} \}$ is an open covering of $S_1$. Since $S_1$ is compact, $\exists I$ finite, $I \subset \mathbb{N}$, s.t $\{V_i: i \in I \}$ covers $S_1$. Let $n:=max(I)$. The class $\{V_1, ..., V_n \}$ also covers $S_1$ and we get the following contradiction   $\emptyset = \bigcap^n_{i=1} S_i = S_n$    So, I don't get the part from "Let $n:=max(I)$..." onwards, especially the contradiction. I have tried applying DeMorgan's Law and the only way the last equalities makes sense is if the union of $\{V_1, ..., V_n \}$ equals the whole metric space, a property I haven't been able to understand from the steps of the proof. This is a corollary to the finite intersection property, so it must have a connection but again I can't quite get it.  Thanks in advance How to make many copies of similar graphs systematically? I want to make various copies of a graph in tikz. The graph I want has 10 vertices. But only has the edges between the vertices a_i,a_(i+1),t,b.  I would like to automatically create 8 copies of this graph. and draw them. I just don't know how to code it. Here is my current code, but it adds all of the edges to the same copy of the graph:  \begin{tikzpicture} [main_node/.style={circle,fill=blue!20,draw,minimum size=2em,inner sep=3pt]}] \node[main_node] (8) at (0:0.5) {b}; \node[main_node] (9) at (180:0.5) {t}; \foreach \x in {0,1,...,7}     \node[main_node] (\x) at (360/8*\x:2) {$a_{\x}$}; \foreach \x in {0,1,...,7}{     \pgfmathsetmacro{\y}{int(mod(\x+1,8))}     \path[draw,thick] (\x) edge node {} (8);     \path[draw,thick] (\x) edge node {} (9);     \path[draw,thick] (\x) edge node {} (\y);     \path[draw,thick] (8) edge node {} (9);     \path[draw,thick] (8) edge node {} (\y);     \path[draw,thick] (9) edge node {} (\y);    }   I want each of the edge sets to be drawn seperately. How do I view the SQL generated by the Entity Framework? How to show (or hide) a hidden file I wanted to add classpath to my JDK. While searching a way to do it I noticed everyone open .profile file using terminal. But when I want to open and edit it with a text editor I couldn't see that file in Home folder.  Can someone tell me why is this. And also if possible how can I access .profile in home folder the GUI way. How do I kill processes in Ubuntu? How do I kill all processes running by my own non-root account?  I have some spinning smbd  processes that I caused from my windows machine and so I telnetted into the linux server and I want to kill those spinning processes.   I don't have authority to restart services or reboot the machine. Duplicate questions on other SE sites? I recently asked a  on security.stackexchange.com. The question was related to XSS so in my opinion it belonged to the security website.  There was a comment on the question saying that a similar question exists on SO and my question was a duplicate (I think he gave it a down vote). The guy was right but the question was asked on another website (SO). There may be a case when person asking a question might not have an account with the other website.  Is it a good practice to mark questions duplicate if you have seen a similar question on some other website? New "[tag:" syntax interferes with Markdown links Links in [link text][number] format don't work properly if they follow a tag using the new [tag:tagName] format. Here's the result of [tag:python] [gold badge page][1]:      [gold badge page]   Putting the tag inside the link is worse. Here's the result of [[meta-tag:bug] some text][2], where [2] is google.com:        The part of the link outside the tag just disappears silently.  EDIT: To be more precise, the entire link to [2] disappears. The markup that is produced contains (invalid) nested anchor tags, as shown here from Firefox's "View Source":  &lt;a href="http://google.com" rel="nofollow"&gt;&lt;a href="/questions/tagged/bug" class="post-tag required-tag" title="show questions tagged 'bug'" rel="tag"&gt;bug&lt;/a&gt; some text&lt;/a&gt;   So the tag is still a link, but it is a link to the tag page, which is the behavior it would have if the link to [2] didn't exist at all. The user's desired behavior in this case is... ambiguous, to be charitable.  EDIT 2: I briefly included markup from Firebug here, but it turned out to be irrelevant. It has now been removed to improve readability. See  if you're interested. Why are comments overlapping the sidebar? On , the comments are overlapping the related questions sidebar. Is this something to do with the weird formatting of the first comment?    Browser: Mozilla/5.0 (Windows NT 6.0; rv:16.0) Gecko/20100101 Firefox/16.0 Is there a way to monitor an SSD state and predict its failure in case of active read-write usage? As far as I know, the only con against switching to an SSD except its price is the tendency to fail soon (relatively to conventional HDDs) in case used in active read-write operation. Is there an efficient way to predict the failure? I am just looking for some clarification on this exercise:  Let $A = \{a,b,c,d\}$. Give an example of a relation $R$ on $A^2$ which is reflexive, symmetric, and not transitive.  I understand that if I was only dealing with $A$ and and not $A^2$ I could give an answer similar to:  $R = \{(a,a),(a,b),(a,d),(b,a),(b,b),(c,c),(d,a),(d,d)\}$  Here $R$ is reflexive, symmetric, and not transitive.  What is confusing me is the fact that we have $A^2$. I am not sure what I am missing here. I am looking through my book to see if I can figure this out, but if someone could help shed some light on this it would be appreciated.  Thanks,  Tony Aliens want to destroy all dogs because they are seen as next step in evolution beyond Man I read a SF short story years ago, I think it may have been in high school back in the 1970s. Aliens come to earth, to kill all the dogs, because they see Man as destroying himself, and dogs as evolving to take Man's place, thus being a threat to the aliens. Humanity agrees to kill all the dogs to get rid of the aliens, but in fact have taken border collies (?) deep underground in order to save them and ensure that they evolve.  Does anyone know the title/author of this short story?  Thank you in advance for your assistance. Change in "under review" date Anbox snap installation fails I'm trying to install Anbox in my new Ubuntu 16.04 using instructions from  . It seemed to work, but I got no icon in my dash, so I suspect that the installation is not complete. With Synaptic  Package Manager I can see that anbox-common &amp; anbox-modules-dkms are installed, but I have no icon in my dash, so I tried running   sudo snap install --edge --devmode anbox   and got this error:  error: cannot install "anbox": Get    https://search.apps.ubuntu.com/api/v1/snaps/details/core?channel=stable&amp;fields=anon_download_url%2Carchitecture%2Cchannel%2Cdownload_sha3_384%2Csummary%2Cdescription%2Cdeltas%2Cbinary_filesize%2Cdownload_url%2Cepoch%2Cicon_url%2Clast_updated%2Cpackage_name%2Cprices%2Cpublisher%2Cratings_average%2Crevision%2Cscreenshot_urls%2Csnap_id%2Csupport_url%2Ccontact%2Ctitle%2Ccontent%2Cversion%2Corigin%2Cdeveloper_id%2Cprivate%2Cconfinement%2Cchannel_maps_list:    dial tcp: lookup search.apps.ubuntu.com on [::1]:53: read udp    [::1]:54255-&gt;[::1]:53: read: connection refused   What am I doing wrong? Why was the connection refused? According to the instructions, it seems this is the correct command to install it.  ps: I'm not that familiar with Linux, I'm more of a Windows guy, trying to learn Linux. How to learn commutative algebra?