apt update Error. Every Reboot first two times. This is normal?
How can I solve "Be aware that removing the lock file is not a solution and may break your system"?
Name of component on output side cable of a DC power adapter? For a CDF that is not strictly increasing, i.e. its inverse is not defined, define the quantile function   $$F^{-1} (u) =\inf \{x: F(x) \geq u \},\quad 0&lt;u&lt;1. $$  Where U has a uniform $(0,1)$ distribution. Prove that the random variable $F^{-1} (u)$ has cdf $F(x)$.  In case of a strictly increasing CDF the proof is quite easy because the inverse is defined. Define $X=F^{-1} (u)$  $$ P\left[X&lt;x \right]=  P \left [F^{-1} (U) \leq x \right]= P \left[U \leq F(x) \right] =F(x)  $$  But how do I accomondate the nondecreasing CDF whose inverse is given by the quantile function? I am a begginer so any help is welcome. Thank you. How to find the matrix of a quadratic form? I was wondering. If I have a bilinear symmetric form, it is easy to find its matrix. But, when I have a quadratic form, which is the procedure to do that?  I heard that one possibility is: If $q$ is my quadratic form, then $$f(x,y) = \frac{1}{4}q(x+y) - \frac{1}{4}q(x-y)$$ is the bilinear symmetric form associated, so the method reduces to find the matrix of $f(x,y).$   The point is that seems a little noising... How to find, in practice, the matrix of quadratic form?  Thanks in advance. I've been looking around and I can't seem to find an automatic (i.e. buzz- or Twitter-like) way to follow users inside Stack Exchange. Why haven't the developers added such a feature? It could help beginner users follow other beginners with the same interests. We would be able to learn from each others' questions and pitfalls. Also, it would reduce double posting. UK visa: unsigned application form How can I search in another language? What is a serialVersionUID and why should I use it? Eclipse issues warnings when a serialVersionUID is missing.       The serializable class Foo does not declare a static final   serialVersionUID field of type long   What is serialVersionUID and why is it important?  Please show an example where missing serialVersionUID will cause a problem. How is light affected by gravity? Jquery - change event firing on page load How do I get my Python program to sleep for 50 milliseconds? How do I get my Python program to sleep for 50 milliseconds? Only Guest User login is Available in my new Dell Vostro Laptop I bought a New Dell Vostro 3558 Laptop today. Ubuntu was pre-installed in that. However, i am facing the below 2 issues in it.   Only Guest user login is available. Linux Terminal is not working in Guest user login   Could someone please advise what i should do now. Why does thermal radiation only occur at infrared and visible frequencies? The resources that I've checked out seem to say thermal radiation only occurs in the infrared and visible spectrum. For example my heat transfer textbook and the Wikipedia page on .  In my mind thermal radiation is just energy emitted as a result of internal collisions from temperature. So, since temperature can range from 0K to huge numbers, I would think you would have a similar range of emitted energies. So then thermal radiation could occur throughout the whole of the electromagnetic spectrum. My Logitech G5 Laser mouse has 9 buttons but it's SetPoint software only allows 5 of them to be used as "mouse buttons" and the remaining 4 can only be assigned special windows functions (Forward, Back, Cruise Up, etc) or Keystroke Assignments.  Many of the games I play will take up to 10 "MOUSE BUTTON" inputs for in-game actions but wont recognize the remaining 4 buttons even when assigned keystroke assignments.  Is there a way to make these last 4 buttons "Generic Buttons" as well as buttons 3,4,and 5? (1 is left click and 2 is right click).  My other question is if the above is not possible, maybe I can use AutoHotkey to remap keystrokes as assigned by my SetPoint software to mouse button commands?  If so how? Prove that $\sum_{r=1}^nr(r+1)=\frac{n(n+1)(n+2)}{3}$ using induction $$\sum_{r=1}^nr(r+1)=\frac{n(n+1)(n+2)}{3}$$  could you help me with how exactly I work this out? Suggested Edit overwritten by OP edit I found this , but I am not sure if this is the same issue.  On , I did some reformatting of the indentation in the code block to make it a bit more readable and it was  for peer review. A few minutes later, it appears the OP made an edit that added some additional code. It looks like my suggested edit was applied when the OP saved his/her edit, and it looks like he got the "credit" for the edit.  I'm not really concerned about the 2 rep points; I'm more curious why this happened and if this is a bug (or limitation) in the editing feature, or if this is known/intended behavior?  Note that this is not a suggested edit that's overridden by a concurrent edit: the recorded edit starts from the post-suggested edit state (and in fact can be identical to it, as in  ). Schengen visa refusal on threat to public policy, security, health I've shown the existence of unique square roots of all positive rational numbers, so now I want to prove that the square root is monotone:   $0&lt;a&lt;b$ if and only if $\sqrt{a} &lt; \sqrt{b}$ In what order should you do linear regression diagnostics? In linear regression analysis, we analyze outliers, investigate multicollinearity, test heteroscedasticty.   The question is:  Is there any order to apply these? I mean, do we have to analyze outliers very firstly, and then examine multicollinearity? Or reverse?    Is there any rule of thumb about this? Why is the Night's Watch so depleted at the start of ASOIAF? At the start of AGOT, the total number of the Night's Watch is said to be less than a thousand. During Aegon's conquest, the Watch numbered ten thousand men. Out of the nineteen castles on the wall, only three are manned today. Castle black itself is once said to have housed 5000.   This rapid deterioration doesn't make sense to me from a world-building perspective. The NW have continued to maintain themselves pretty well for nigh on 8000 years (if the tales can be believed that is, Sam Tarly finds no written evidence of Lord Commanders earlier than #673, which suggests that 8000 years may be an inflated 'legendary' number).   Whereas in the real world, one of the oldest and most venerable institutions, the Catholic Church, has been around for less than 2000 years and has been administered by ~200 popes. The Night's Watch has had a few rocky years, sure, but for it to maintain itself so well for so long and then deteriorate only in the last 300 years seems strange to me.   The NW has two purposes. The ostensible one of defending against the Others, and the (arguably much more real, at least at the start of AGOT) purpose of serving as a dumping ground for the 'losers' of Westeros. By 'losers', I mean the people on the losing side of various wars and political battles, as well as criminals and n-th sons of noble houses with nothing to inherit.  I am currently reading through Fire and Blood, and was struck by one chapter, where an armed revolt of members of the Faith were defeated by Maegor, and 2000 brothers were forced to take the black. Those sorts of numbers don't exist in the recent histories it seems.   One would expect that after Robert's Rebellion, there would be a surfeit of defeated Targaryen loyalists who were forced to take the black, but apart from a smattering of named characters (including Ser Alliser Thorne), there seem to be hardly any Night's watch recruits from recent wars.  Given the way the Night's watch is continually bolstered by the losers of wars and by criminals and other people who elsewise have nothing going for them, why, at the start of AGOT, is the force so depleted? I am trying to draw a cantor set in LaTeX and I am having issues doing this. I am trying multiple \put commands, but they just go to the right of one another. Does anyone know how to do this?  Any help would be much appreciated.