Can't find a command for actuarial angle
Annuity notation in LaTeX
How do you join on the same table, twice, in mysql? I have 2 tables. One (domains) has domain ids, and domain names (dom_id, dom_url).  the other contains actual data, 2 of which columns require a TO and FROM domain names. So I have 2 columns rev_dom_from and rev_dom_for, both of which store the domain name id, from the domains table.  Simple.  Now I need to actually display both domain names on the webpage. I know how to display one or the other, via the LEFT JOIN domains ON reviews.rev_dom_for = domains.dom_url query, and then you echo out the dom_url, which would echo out the domain name in the rev_dom_for column.  But how would I make it echo out the 2nd domain name, in the dom_rev_from column? How does an arcane focus work with an Eldritch Knight? My PC is an Eldritch Knight. I was wondering what is an Arcane Focus? Do I need to have it in my hand? If I get the War Caster Feat does my arcane focus become obsolete? I am new to Ubuntu. I am Using Ubuntu 18.04 along with Windows10. I have gone through the below Q&amp;A and could able to change the name of Ubuntu,      But   if i edit the Ubuntu OS name to my choice, it is then adding "GNU/Linux" at the end. for ex. if i want "Ubuntu 18.04" it is then showing as "Ubuntu 18.04 GNU/Linux". how to avoid this text "GNU/Linux" how to edit the name to my choice which is shown as "Windows Boot Manager (on /dev/sda1)"        Update: I Confirm about the text "GNU/Linux" is solved by @Terrance comments. I still need to try about windows entry.      Final Update: Solved.    I thank @Terrance, @Oldfred, @WinEunuuchs2Unix. All the three methods are working great. i felt the small script is awesome and very very easy to use. which is written by WinEuuuchs2Unix. According to  , gold badge holders can now unilaterally close questions as duplicates. I hold seven gold badges for tags on SO, which means I can, on my own, close questions as duplicates for those tagged questions.  Simply put: DO NOT WANT.  However, I do not see any ability in SO (the only SE site I spend much time in) to opt out of any privileges, let alone this one.  Is there a spot that I'm just not seeing that allows me to turn off this new privilege? parsing a date string from FTPClient.getModificationTime() Related:   I have put a bit of commentary enumerating my confusions in parentheses  I read in Black Holes and Time Warps (Kip Thorne), that quasars can generate their jets from four different processes. These all involved the accretion disk, but there was one which doesn't make quite as much sense. It was called the Blandford-Znajek process, and it involved magnetic field lines carrying current.  The process was visualized in two ways. A black hole, with magnetic field lines, is spinning. In the first visualisation (viewpoint actually), the magnetic field lines 'spin' along with the black hole, and nearby plasma is anchored onto the field lines by electrical forces (where did the electrical fields come from?). The plasma can slide along the field lines but not across them (why?).  Since the field lines are spinning, centrifugal forces will fling them up and down the field lines, forming jets.  The other viewpoint is this, and it makes even less sense (to me that is, I haven't had a formal education in GR): The magnetic fields and the swirl of space generate a voltage difference across the field lines (Why? How?). The voltage carries current across the magnetic field lines (why are the field lines behaving like wires?). This current travels across plasma, which accelerates it, creating the jets.  Now the main thing that doesn't make sense, is that magnetic field lines are behaving like wires. Why would they? I suspect the answer lies hidden somewhere in the equivalence of EM waves in different frames, but I can't think up any convincing argument from that side.  If the answer involves GR equations, you don't need to solve it here (wouldn't make sense to me), but if you have to, just refer to the equation and what you did to it, along with the final result. Thanks! Showing that $\int_0^\infty x^{-x} \mathrm{d}x \leq 2$. Inequality with exponents $x^x+y^y \ge x^y +y^x$ Let $x,y$ be positive numbers. Prove that $x^x+y^y \ge x^y +y^x$.   This question appeared in Summer 1991 Russian Olympiad team test. Apparently, I tried to come up with different approach such as Jensen, Karamata's inequality and nothing works so far. I just need a discussion here. Hints are not necessary. Find where java class is loaded from How can light be called electromagnetic if it doesn't appear to be electric nor magnetic?  If I go out to the sunlight, magnets aren't affected (or don't seem to be).  And there is no transfer of electric charge/electrons (as there is in AC/DC current in space).   In particular, the  (which light is supposed to be composed of) have no electric charge (nor do they have ).   I'm looking for an explanation that can be appreciated by the average non-physicist Joe. Find $cot\space x_n$ if $sin(x_{n+1}-x_n)+2^{-(n+1)}sin\space x_nsin \space x_{n+1}=0$ for $n\ge1$ Also Given     Suppose $x_1=tan^{-1}2&gt;x_2&gt;x_3&gt;......$ are positive real numbers   I cannot understand as to how I should approach but I have a hunch which is a bit hand-wavy way to prove it but tried to show that  $lim_{n \to \infty}x_n =\dfrac{\pi}{4}$ (For the proof see my edits in @hypernova's answer)  But can anybody prove it and then use it to find $cot \space x_n$ please? There is a sentence:     No sooner had he sat down than he fell asleep.   I just do not understand, is this an inversion? And if so, I still do not understand the sentence. ASP.NET: Is there a way that I can simply pass a model into a view and render it to a string? Questions about right ideals What is the meaning, usage and formality of the greeting "What's up"? A subring of the field of fractions of a PID is a PID as well. Let $A$ be a PID and $R$ a ring such that $A\subset R \subset \operatorname{Frac}(A)$, where $\operatorname{Frac}(A)$ denotes the field of fractions of $A$. How to show $R$ is also a PID?   Any hints? How can I 'join' an array adding to the beginning of the resulting string the first character to join? Make a fake random distribution? Sometimes a "real" random event seems unfair and makes players frustrated. For instance a enemy has probability of 20% to cause double damage("critical hit"). Thus he could make 4 critical hits in a row with 1/725 probability. It's not as small as it sounds.  I hope the probability could be adjusted after each hit. If the player just got a critical hit, the probability decreases for the next hit. Otherwise it increases.  Is there a mathematical model for this behaviour? I'm looking to install 32-bit windows with IIS to dual-boot with my 64-bit edition of windows on a laptop. I have a ten gig partition on my harddrive - is this large enough for a simple Windows install and a few programs?   I've never dual booted before, so I'm not quite sure how easy it is to mess up the process. Can you recommend any tutorials on how to set up a dual-boot configuration on Windows? Is the sizeof(some pointer) always equal to four?