Witcher 2 how to drop a bomb
How do I destroy Nekker nests?
How to prove that minimum of two exponential random variables is another exponential random variable? How can I prove that the minimum of two exponential random variables is another exponential random variable, i.e. Z = min(X,Y) I want to start an Xorg server (which should only feature a minimal xterm terminal emulator from a newly created &quot;pristine&quot; tty). I have thought this to be as simple as issuing a xinit or maybe a startx however both have failed me. Therefore the question: How to manually run/init/start a Xorg server on a different VT/TTY? here the Longer background story to the question at hand: This is the backgroud and what I have tried already: Looking at man openvt I was able to run a shell on a newly created tty (or vt, cannot tell precisly the different vt&lt;&gt;tty) like this:  $&gt; sudo openvt -s /bin/bash  the -s of causes the direct switch to that new tty/vt on that new tty I wanted to manually start a Xorg server which according to man xinit should start with a minimal xterm application. On the new shell on the switched to tty I (created via openvt) I hence issues this command:  $&gt; su -c 'xinit xterm -display :4 -- :4' - mahr &amp;&gt;/tmp/output  and I receive this output $&gt; cat /tmp/output X.Org X Server 1.19.6 Release Date: 2017-12-20 X Protocol Version 11, Revision 0 Build Operating System: Linux 4.4.0-148-generic x86_64 Ubuntu Current Operating System: Linux scitech 4.15.0-70-generic #79-Ubuntu SMP Tue Nov 12 10:36:11 UTC 2019 x86_64 Kernel command line: BOOT_IMAGE=/vmlinuz-4.15.0-70-generic root=/dev/mapper/ubuntu--vg-root ro Build Date: 03 June 2019  08:10:35AM xorg-server 2:1.19.6-1ubuntu4.3 (For technical support please see http://www.ubuntu.com/support)  Current version of pixman: 0.34.0     Before reporting problems, check http://wiki.x.org     to make sure that you have the latest version. Markers: (--) probed, (**) from config file, (==) default setting,     (++) from command line, (!!) notice, (II) informational,     (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: &quot;/home/mahr/.local/share/xorg/Xorg.4.log&quot;, Time: Thu Nov 28 10:57:53 2019 (==) Using system config directory &quot;/usr/share/X11/xorg.conf.d&quot; (EE)  Fatal server error: (EE) parse_vt_settings: Cannot open /dev/tty0 (Permission denied) (EE)  (EE)  Please consult the The X.Org Foundation support       at http://wiki.x.org  for help.  (EE) Please also check the log file at &quot;/home/mahr/.local/share/xorg/Xorg.4.log&quot; for additional information. (EE)  (EE) Server terminated with error (1). Closing log file.  Session terminated, terminating shell...xinit: giving up xinit: unable to connect to X server: Connection refused xinit: unexpected signal 2  ...terminated. What does 'Ign' , `Get` or 'Hit' mean when running an apt-get update? I had a bunch of errors in the output of sudo apt-get update:  duplicate entries and 404 not found errors.  Figured those out, I hope: I removed PPAs that didn't have any packages associated with them, then I removed out a duplicate entry in /etc/apt/sources.list.  It seems I have royally buggered it up.  Now most of the lines say Ign when I do sudo apt-get update.  How do I go about straightening out what I have screwed up?  I need to get rid of these Igns that are all over the place.  There are about 50% (eyeball guess) Igns! I'm close to maxing out my character and I want to beat Ganon solely for the TRUE ending, but I'm too scared of losing some of my personal favorites from the Guardian Spear++ to fighting those damned Guardians (it was so fun).  So, after beating Ganon    Do monsters disappear? - Including the corrupted Guardians, but also the blood moons, I don't want to just face off against the Yiga Clan... Am I gonna run out of resources? - As a survival game Zelda BOTW has some emphasis on the survival genre but to me it is a survival-esque action-adventure game. Are special weapons still available when you max out? - Like the Savage Lynel Spears or Swords) I need to implement the following circuit in LTSpice but I don't know if my schematic is ok. Also, I don't know what  values for I should use for Cinf and R2.  The following constraints are imposed:   VCC= 10V VCM = 1.5V Vgis a sine wave with a frequency of 1 kHz. Its amplitude will be chosen so as to ensure minimal distortion of the output signal (i.e. v0 should also be a sine wave) R1= 15kΩ.    I need to choose a value for R2 and Cinf in order to have a (theoretical)gain value Av=1500.   How can I compute the theoretical expressions of the DC collector currents of bipolar transistors Q1–Q8, considering VBE≈ 0.6V and the theoretical expression of the small-signal voltage gain Av= vo/vg?   The first picture is the schematic and the second is the LTSpice implementation.  What I found is that:   ICq5=ICq6=ICq7=ICq8=(Vcc - Vbe)/R2 ICq1=ICq2 = [ICq7 / 2 ] * [Beta/(Beta+1)] ICq4=iCq2-current of Q5 ICq3=ICq1-current of Q3-current of Q4  Beta in my case is 182.1 because I'm using a BC847A transistor. A=Vo/Vg = Gm_q2 * Beta_q5 * R1Gm_q2=ICq2 / Vt that is approx 40*ICq2   How can I find the value of R2? This is what I have now, an sine like wave for Vg What is the distribution of the sum of non i.i.d. gaussian variates? If $X$ is distributed $N(\mu_X, \sigma^2_X)$, $Y$ is distributed $N(\mu_Y, \sigma^2_Y)$ and $Z = X + Y$, I know that $Z$ is distributed $N(\mu_X + \mu_Y, \sigma^2_X + \sigma^2_Y)$ if X and Y are independent.  But what would happen if X and Y were not independent, i.e. $(X, Y) \approx N\big( (\begin{smallmatrix} \mu_X\\\mu_Y \end{smallmatrix}) , (\begin{smallmatrix} \sigma^2_X &amp;&amp; \sigma_{X,Y}\\ \sigma_{X,Y} &amp;&amp; \sigma^2_Y \end{smallmatrix}) \big) $  Would this affect how the sum $Z$ is distributed? A matrix and its transpose have the same set of eigenvalues/other version: $A$ and $A^T$ have the same spectrum Let $ \sigma(A)$ be the set of all eigenvalues of $A$. Show that $ \sigma(A) = \sigma\left(A^T\right)$ where $A^T$ is the transpose matrix of $A$. What is the best way to explain how to choose between "its" and "it's"? How to set the fully qualified hostname on CentOS 7.0? How do I set the fully qualified hostname on CentOS 7.0?  I have seen a few posts online for example using:  $ sudo hostnamectl set-hostname nodename.domainname   However, running domainname returns nothing:  $ domainname (none)   Also:  $ hostname nodename.domainname   However,  $ hostname -f hostname: Name or service not known $ hostname -d hostname: Name or service not known   Some debug output:  $ cat /etc/hostname nodename.domainname  $ grep ^hosts /etc/nsswitch.conf hosts:      files dns I vaguely remember a SciFi novel from my younger days, where scientists discover "alternative" forms of power beside electromagnetism.  I do not remember the specific forms, but it was something along the lines of "electrogravity", "magnetogravity" etc. -- you get the idea. If I remember correctly, the effects of these power forms were basically psionic / magic in nature.  Unfortunately I remember very little of the actual plot, and couldn't put it into words with any coherency. Some treachery from within the group of scientists, perhaps some involvement of aliens? I cannot really remember. I just remember I enjoyed the story very much, and would like to re-read it.  The title could be "The fifth column" or similar -- then again I might be confusing two seperate novels.  I know that's not much, sorry. Anyone remembers this? Integral $\int_{1}^{2011} \frac{\sqrt{x}}{\sqrt{2012 - x} + \sqrt{x}}dx$ Evaluate:  $$\int_{1}^{2011} \frac{\sqrt{x}}{\sqrt{2012 - x} + \sqrt{x}}dx$$  Using real methods only.  I am not sure what to do.  I tried finding a power series, which was too ugly.  I just need some hints, not an answer to do this integral, this is from the MIT Integration bee 2012. If temperature makes particles vibrate faster, and movement is limited by the speed of light, then I would assume that temperature must be limited as well. Why is there no limit? Show that if $p$ is prime then $\Bbb Z_p$ is a field Check my proof please.  Let $\Bbb Z_p:=\Bbb Z/p\Bbb Z$ be the quotient ring modulo $p$. I want to prove that if $p$ is prime then $\Bbb Z_p$ is a field.  Known facts about the quotient rings of the kind $\Bbb Z_n$ (I dont list all the characteristics of a ring, just some ones):   They are commutative rings with unity. $[0]=[n]$ is the identity of addition or zero. Then $[n]+[a]=[a]$ and $[n]\cdot[a]=[n]$ for all $[a]\in\Bbb Z_n$. $[1]$ is the multiplicative identity or unity. Then $[1]\cdot[a]=[a]$ for all $[a]\in\Bbb Z_n$. The addition is defined as $[a]+[b]=[a+b]$, and the multiplication is defined as $[a]\cdot[b]=[ab]$. $[a]=[b]$ means that exists $z\in\Bbb Z$ such that $a=b+nz$. $|\Bbb Z_p|=p$.   A ring $\Bbb Z_p$ dont have zero divisors, i.e. doesnt exist $[a],[b]\in\Bbb Z_p$ distinct of $[p]$ such that $[a]\cdot[b]=[p]$. Proof by contradiction: suppose that exists such $[a],[b]$ distinct of $[p]$ that are zero divisors. Then exist some $z_j\in\Bbb Z$ such that:  $$(a+pz_1)(b+pz_2)=pz_3\iff ab+pz_4=pz_3\iff ab=pz_5$$  but this is a contradiction with the assumption that $a,b\neq p$ and $p$ prime, so dont exist divisors of zero on any $\Bbb Z_p$.$\Box$  For any $[a]\in\Bbb Z_p$ distinct of $[p]$ exist $[b]$ such that $[a][b]=[1]$. Because $\Bbb Z_p$ dont have zero divisors and is finite for some $[a]\neq[p]$ we have that if $[b]\neq[c]$ then $[a][b]\neq[a][c]$. Proof by contradiction: if $[a][b]=[a][c]$ in the above conditions then  $$[a][c]=[ac]=[ab]=[a][b]\iff ac+pz_1=ab+pz_2\iff a(c-b)=pz_3$$  for some $z_j\in\Bbb Z$. But $pz_3\in[p]$, then $[a][c-b]=[p]$ but because there are no zero divisors in $\Bbb Z_p$ then or $[a]=[p]$ or $[c-b]=[p]$ what contradicts the above conditions.$\Box$  Because $[a][b]\neq[a][c]$ for $[a]\neq[p]$ and $[b]\neq[c]$ then for any $[a]\neq[p]$ we have that  $$[a]\cdot\Bbb Z_p=\Bbb Z_p\implies \exists [b]\in\Bbb Z_p:[a][b]=[1]$$  In other words: every element of $\Bbb Z_p$ but $[p]$ have a multiplicative inverse as stated above.$\Box$  Because $\Bbb Z_p$ is a commutative ring with $[1]\neq[0]$ and have multiplicative inverse for all their elements but $[p]=[0]$ then $\Bbb Z_p$ is a field.$\Box$ I have defined my own custom vim file type with highlighting etc.  I would like to open it using the terminal based vim when I double click on it.  I am using mac os x.  Any pointers on how to start on this? An inequality about Stirling numbers For all positive integers $n,r,k$ that $n=rk$, how to prove the inequality $$(r-1)!^k\le \frac{c(n,k)}{S(n,k)}\le (n-k)!$$ $c(n,k)$ is unsigned Stirling numbers of the first kind and $S(n,k)$ is Stirling numbers of the second kind.  Any help would be appreciated! Permanently removing apache2 It seems a simple apt-get remove apache2 does not completely remove apache2 as I can still see it on one of the processes when running top. How does one remove apache2 completely on his ubuntu server?  It's not removed indeed:  ~# which apache2 /usr/sbin/apache2 ~# whereis apache2 apache2: /usr/sbin/apache2 /etc/apache2 /usr/lib/apache2 /usr/share/apache2 /usr/share/man/man8/apache2.8.gz   But when I do apt-get remove apache2 again:  # apt-get remove apache2 Reading package lists... Done Building dependency tree Reading state information... Done Package apache2 is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Show that there are $ a,b \geq 0 $ so that $ |f(x)| \leq ax+b, \forall x \geq 0.$ I have the following exercise: $$f:[0, +\infty) \rightarrow \mathbb{R} \text{ uniformly continuous  } .$$ $$\text{Show that there are } a,b \geq 0 \text{ so that } |f(x)| \leq ax+b, \forall x \geq 0.$$ $$$$ $f:[0, +\infty) \rightarrow \mathbb{R} \text{ uniformly continuous  } :$ $\forall \epsilon &gt;0 \exists \delta &gt;0 \text{ such that } \forall x,y \in [0, + \infty) \text{ with } |x-y|&lt; \delta \Rightarrow |f(x)-f(y)|&lt;\epsilon$ $$$$ How can I continue?? For all $X \geq 1$,$\sum\limits_{1 \leq n \leq X} \mu(n) \left[\frac{X}{n}\right] = 1.$ I'm currently sitting with the following number theory problem:  Prove that for all $X \geq 1$, $$\sum_{1 \leq n \leq X} \mu(n) \left[\frac{X}{n}\right] = 1.$$  A few ideas I have tried: Using that $[x]=x - \{x\}$ which I couldn't make out to bring anything. Switching around on the summation variables, like $$\sum_{d \leq N} \mu(d) f\left( \frac{n}{d} \right) = \sum_{d \leq N} \mu \left( \frac{d}{n} \right) f(d)$$ but that didn't seem to bring anything.  I tried writing out the first few terms, which give $$\mu(1) [X] - \left[\frac{X}{2}\right] - \left[\frac{X}{3}\right] - \left[\frac{X}{5}\right] + \left[\frac{X}{6}\right] - \left[\frac{X}{7}\right] - \left[\frac{X}{8}\right]$$ but I can't seem to find a system where it simply reduces to one!  What do you think? Would this look natural:     StackExchange is a helluva site! I found out about this site at Facebook.    Or should we use the preposition on:     StackExchange is a helluva site! I found out about this site on Facebook.    Or are both okay?   (Inspired by a ) What exactly happened with Dr. Crusher's husband and Captain Picard?