I have a problem..  I want to update my kernel, but I have a notice when I install the new kernel like this please install the kmod first.  so I install kmod, but when I install the kmod, my terminal say  Reading package lists... Done Building dependency tree        Reading state information... Done Package kmod is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'kmod' has no installation candidate   why?? and when I check dpkg -l kmod i have this   ||/ Name           Version        Description +++-==============-==============-============================================ in  kmod           &lt;none&gt;         (no description available)   can you help me to update my kernel, my friend? I'm newbie ubuntu user. My kernel 3.5.0-23-generic .. Thank You ..
Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc
Prove by contradiction (not using a calculator) that $\sqrt6 + \sqrt2 < \sqrt{15}$? How to use stars and bars for solving number of integral solutions to an equality? How to use the  method?  Say I want to find number of combinations I can get with $x_1+x_2+x_3+x_4=22$,  where $x_i\in\mathbb{N}$.  Is this the correct time to apply the method?  This is being repurposed in an effort to cut down on duplicates, see here:     and here: Commutator Subgroup and the Largest Abelian Quotient Good day. I'm not too sure how I should go about asking my question, so if it is in anyway confusing, feel free to edit it.   In my Group Theory course we defined and showed a few properties of the commutator subgroup $[G,G]$ of a group $G$. And then we stated and proved a lemma in lecture that I'm having some difficulty wrapping my head around. I'll state it here for clarity.  Lemma a) The commutator subgroup $[G,G]$ of $G$ is a normal subgroup of $G$. b) The quotient group $G / [G,G]$ is the largest abelian quotient of G in the sense that every homomorphism $\varphi : G \to A$ where $A$ is an an abelian group, induces a unique homomorphism $\bar \varphi : G/[G,G] \to A$ so that $\varphi =\bar \varphi \circ \pi$ where $\pi : G \to G/[G,G]$ is the quotient homomorphism.  Now, it's not the proof of this lemma that I'm having trouble with, it's the italicized text that is messing with me. I completely understand what it is that the italicized text is saying, I'm just not too sure why it is that the property gives us the "largeness" that is claimed. I can see that the above forces $G$ to "pass through" $G/[G,G]$ before it "reaches" $A$ (I apologize for the casual terminology), so I can sort of see why $G/[G,G]$ should be the largest quotient, in a non-rigorous sort of way.  Overall I'm very confused. Perhaps I'm missing something very simple. Any help or nudges in the right direction would be much appreciated.   As a side note I did try a search on Google and here on Stack Exchange and couldn't find anything that answered my question. So if I missed something obvious, then my apologies. Thank you in advance. 1 Plot, 2 Scale/Axis Custom cross-reference formats (e.g. "Equation 1" instead of just "1") Mars needs water and women I read this book in high school too many years ago for me to think about. Martian colonist are raiding earth's oceans for water and because of the conditions on Mars where only male children are conceived, they are also on the look out for young women as potential mates. Our main character while on a raid, bags not only a young woman but her brother as well. Returning to Mars they find that Earth has attacked Mars can't remember much more. Can I boot memtest86+ if I'm using UEFI? Downloaded the Ubuntu 16.04.2 .iso install disk and flashed it onto a USB stick.  Booting on the USB stick, there is no memtest86+ option (along with "Try Ubuntu").  Is there a way to add it to the install options?  (it's for a UEFI boot PC running normally Windows, its owner does not want to install Ubuntu. "memtest86+" is completely free (unlike "memtest86"), but is quite old, and does not offer a UEFI boot - this is why having it within the Ubuntu options makes things easier) How do that charge gets transferred while rubbing? Because of  I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package.   How can this be achieved? While rendering a mesh with smooth shading on, I get a dark region/shadow on certain faces. The effect is more evident when smooth shading is applied to a mesh containing ngons, with the ngons turning black when rendered.   The blackening effect is visible in the viewport too.  How can I solve this problem? When to use "If I was" vs. "If I were"? If I was... If I were...   When is it correct to use "If I was" vs. "If I were" in standard English? $f : S^1 \to\mathbb R$ is continuous then $f(x)=f(-x)$ for some $x\in S^1$ Question is to prove :  $f : S^1 \to \mathbb R$ is continuous then $f(x)=f(-x)$ for some $x\in S^1$  I guess it would be helpful to use intermediate value theorem  Assuming $f(x)\neq f(-x)$ then given any $p\in (f(-x),f(x))$ (assuming $f(-x)&lt;f(x)$) there exists $y\in (-x, x)$ such that $f(y)=p$  I am not very sure of how to use this..   It would be helpful if someone can give some hint which would help me to solve this..  Thank you. I have a Macbook and an iMac, generally I work on my Macbook, but sometimes I need that information on my iMac. My OS is Mac OSX Snow Leopard. Why are mathematical proofs that rely on computers controversial? There are many theorems in mathematics that have been proved with the assistance of computers, take the famous  for example. Such proofs are often controversial among some mathematicians. Why is it so?  I my opinion, shifting from manual proofs to computer-assisted proofs is a giant leap forward for mathematics. Other fields of science rely on it heavily. Physics experiments are simulated in computers. Chemical reactions are simulated in supercomputers. Even evolution can be simulated in an advanced enough computer. All of this can help us understand these phenomena better.   But why are mathematicians so reluctant? How To Reduce Noise In Cycles Render As linguistics student, I have to put more than one thing on a character every now and then. For example, I need to type ā̆. I thought I could simply do that by typing \={\u{a}}, but then the macron is placed above an empty space in front of the character.  How can I solve this? Thanks  P.S. I'm using MiKTeX 2.9, running on Windows 8; in case it might be of use. Can Gmail automatically base "send from" address on the "to" address? Is transferring to another university an option for an unhappy PhD student? I've heard of people transferring between graduate schools because of their advisor moving to another school and taking their students with them.   Do students ever transfer for other reasons? If a student isn't happy at the school they choose, could transferring be an option? Presumably they would frame it as something positive such as "turns out I really want to work with Professor X" rather than "I hate my school", but does this ever happen? Is there a certain timeframe in which this is possible? (Assume it's a 5 year PhD program.)  If the answer varies by subject please mention the subject in your answer.  (Context: many friends have told me that if it turns out I'm not happy with my choice, I can always transfer. My impression is that this is actually difficult since many schools don't accept transfer students and in any case not being able to stick with a program looks bad -- but I don't have evidence either way so wanted to ask people who are in academia. Of course the ideal would be to pick a school one is happy with in the first place!) I would appreciate if someone could help me write the mathematical equation for the seasonal ARIMA (2,1,0) x (0,2,2) period 12. I'm a little confused with how to go about this. I would prefer an equation involving $Y_t , e_t, θ$ and $Θ$. count lines in a file I'm sure there are many ways to do this: how can I count the number of lines in a text file?  $ &lt;cmd&gt; file.txt 1020 lines