My first disk has windows and second disk (not partition) has Ubuntu.   But the first disk was removed during ubuntu installation and plugged back after installation.   Now my system boots with only one OS depending on the disk with higher priority in the boot list.   One of the attached question talks about boot repair or about reinstalling grub-efi. Which is not the case here. My system boots perfectly but based on the drive selected.   The other attached question is valid with the given assumptions being true, which are false in my case.   Is there any way to get OS selection list at boot time?
I have installed Ubuntu 15.10 alongside Windows 10 with UEFI. To install Ubuntu, I chose the option install alongside Windows 10 or something similar to this. Then I created a new partition for Ubuntu and installed it. After installation, the boot menu did not show up. Initially I thought Ubuntu has not been installed, but when I plugged in the USB drive and wanted to install Ubuntu I saw an option of reinstalling Ubuntu on my machine. So, I found out that Ubuntu is installed. Pressing F8 and F12 also does not help. Can anyone help me bring up the GRUB boot menu? In Windows, I also entered the command bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi in cmd, but still the boot menu does not show up.  Reply (Himanshu) : Just boot in bios and, if you can, add boot option with name say ubuntu and path EFI/ubuntu/shimx64.efi. No need for live PCB or anything. Move the boot option to top. This is for dell GUI bios but I assume it works for all. Or you may want to see  or , where you can enable Windows Boot Loader for one boot or forever as you wish, and boot Ubuntu from it. If you want now, you can use the installed Ubuntu terminal to use the commands update-grub to use GRUB instead. (Not enough reputation to answer properly btw.)
Extended Euclidean Algorithm: backward vs. forward Summation of Central Binomial Coefficients divided by even powers of $2$ Whilst working out  the following summation emerged: $$\sum_{m=0}^n\frac 1{2^{2m}}\binom {2m}m$$ The is equivalent to  $$\begin{align} \sum_{m=0}^n \frac {(2m-1)!!}{2m!!}&amp;=\frac 12+\frac {1\cdot3}{2\cdot 4}+\frac{1\cdot 3\cdot 5}{2\cdot 4\cdot 6}+\cdots +\frac{1\cdot 3\cdot 5\cdot \cdots \cdot(2n-1)}{2\cdot 4\cdot 6\cdot \cdots \cdot 2n}\\ &amp;=\frac 12\left(1+\frac 34\left(1+\frac 56\left(1+\cdots \left(1+\frac {2n-1}{2n}\right)\right)\right)\right) \end{align}$$  and terms are the same as coefficients in the expansion of $(1-x)^{-1/2}$.  Once the solution  $$ \frac {n+1}{2^{2n+1}}\binom {2n+2}{n+1}$$ is known, the telescoping sum can be easily derived, i.e.    $$\frac 1{2^{2m}}\binom {2m}m=\frac {m+1}{2^{2(m+1)-1}}\binom {2(m+1)}{m+1}-\frac m{2^{2m-1}}\binom {2m}m$$  However, without knowing this a priori, how would we have approached this problem? How is memory allocated for an implicitly defined multidimensional array in C99? Did other meta-humans enter a coma? In the first episode of The Flash (2014), Barry's struck by lightning, some chemicals fall on him, and he enters a coma for 9 months.  This happens when the S.T.A.R. Labs particle accelerator is turned on for the first time.  9 months later, he wakes up and has powers.  He then starts fighting crime, especially other meta-humans who were created by the same particle accelerator accident.  However, this is all 9 months after the accident, where were the other meta-humans during those 9 months?  The S.T.A.R. Labs people make it sound like they hadn't seen any meta-humans active during the 9 months Barry was out.  Did all people granted powers by the particle accelerator accident also fall into comas?  Why weren't they active heroes/villains during the 9 month gap? $D_8$ as a derived subgroup Every undergraduate student knows that there are (exactly) two non-abelian groups of order 8: Dihedral ($D_8$) and Quaternion ($Q_8$). The group $Q_8$ has many interesting properties; simple of them are: it has unique element of order $2$, all subgroups are normal, etc. A property, which is strange and not obvious, the group $Q_8$ has, is that there is no group $G$ such that $G/Z(G)$ is isomorphic to $Q_8$. On the other hand, $D_8$ has no such property; there are (infinitely many) groups $G$ such that $G/Z(G)$ is isomorphic to $D_8$; example - $D_{16}$.   The question, I would like to ask, is related to a property of $D_8$, which is not shared by $Q_8$. There are (infinitely many) groups whose derived subgroup is $Q_8$; example- $SL_2(3)$. For groups $G$ of order &lt;100, one can check on GAP that $D_8$ is not a derived subgroup of any group. The natural question is then:  Question 1: Does there exist a finite/infinite group whose derived subgroup is equal to $D_8$?  Question 2: Does there exist a finite/infinite group whose derived subgroup is equal to (general) dihedral group $D_{2n}$ of order $2n$ ($n&gt;2$)? I already searched the internet but could not find a solution to this. Maybe it is the same question as  but there was no answer.  I want to render a video with tracking, but the output "loses" color information and gets kind of greyish. I first thought that it is related to the renderer, but it happens in Cycles and Eevee. Therefore i made a sample image, added it to the image sequence editor and rendered it as 1 frame. Resulting in the same problem.  I placed the original image beside blenders output so that you can see the difference. The only idea I came up with is that something with the lighting is not correct but I can't find a setting for that.  I am using Blender 2.80 with the default settings. Only set the output resolution to match the input resolution. One of the things that makes him great is he brings it every night.   I'm pretty sure it should be that make him in the plural, because one of the things is referring to a lot of things and a lot of things should take a plural verb. But I always hear native speakers in America say it in the singular, so with an s.  Another example:     This is one of the responsibilities that comes with greatness and he understands that.   Native speakers always use the verb in the singular (here, comes) even though [I believe] it is grammatically incorrect to use the singular form of the verb there. How to redirect output of a program to a ZIP file? Unstable wifi with intel 8260 [8086:24f3] (rev 3a) on Ubuntu 16.04 running on Lenovo P50 Evaluate $\lim_{n\rightarrow\infty} \int_0^1 f(x^n) dx$ Food in the Star Wars Universe? How do I install Ubuntu alongside a pre-installed Windows with UEFI? Related to the question :  It is well known that   $$\zeta(2n) = f(2n) \pi^{2n}$$  where $f(n)$ is an function in rationals: (the denominator = OEIS : 6, 90, 945, 9450).  Apery proved that $\zeta(3)$ is irrational, and presumably $f(2n+1)$ is so for all (but the latter is open).  But what else is known about $f(2n+1)$? What sort of pattern does it share (if any) with $f(2n)$? Numerically does it fit well? Is there any clue/progress since Apery as to its form? Of course, $f(2n+1)$ may in effect divide out the $\pi$, meaning that somehow $\pi$ is not involved in $\zeta(2n+1)$ in any essential way. How can I compute $\mathrm{Aut}(\mathbb{Z}/4\mathbb{Z}\times\mathbb{Z}/6\mathbb{Z})$? A fellow player is uncooperative with the group and gets GM favoritism. How do I handle this? I actually have two situations but they are interconnected. Our group is currently playing a Dresden game. The GM and one of the players are married. Along with that, he is a new member to the group. I can understand her (the GM) wanting to make him feel welcome but it has gone into the the realm of blatant favoritism. A few examples:   Every idea he has is deemed fantastic, wonderful, awesome and is always successful. Most of the time he doesn't have to roll to see if he succeeds; he just does. After a series of major setbacks to the other player's characters, I joked that her husband was the only one left to mess with. Her answer to that was that she would absolutely not be messing with him in the game. He and his character were safe from that. In the last session, he and another player had to make the same roll using the same skill for the same information. He needed a fair to succeed. The other player needed a great. Not the first time that has happened.    The second part of this has to do with him as well. As I said, he is new to the group. When we were discussing a game to play, it was made clear that it would be cooperative. We would all be working together to a common end. However, he will not- I mean ever- share any information with the rest of the group. No matter how vital or needed that information is to advance the story, he just smiles and says he's got nothing. To try and get around this problem, a group aspect was created. That way if a situation or information that everybody needed to know came up, a fate chip could be played and anyone who wanted to be a part of it could be present. He is totally abusing it. Now, instead of just not telling us anything, he adds give me a fate chip and maybe I'll tell you something. It's like he is trying to beat us at the game and that is not the way it was set up.    So, the question to these two situations is what do I do? How do I handle this in a rational and sensitive way? To complicate things further, the GM is my best friend. He is her husband. I don't want to put her in the middle but I am about ready to quit the game. I am tired of it being his game and everyone else being bit players. Should I talk to her or should I talk to him? If anyone has had experience with this, any advice would be appreciated. From :   (formal) showing great care and effort in your work synonym: diligent  (formal) working very hard and taking great care that everything is done as well as it can be synonym: diligent  (formal) showing care and effort in your work or duties  These definitions look alike. What they have in common is that these words mean to take care and to put effort into your work. All words are formal. None of these seems to be a proper term in a specific field, e.g. medical, law. I also looked at  to get more details. This adds the connotation of steady and earnest to diligent and unremitting attention and persistent application to assiduous. But in the end, these additional information are again describing an equal thing, i.e., continuously doing your work. The entry on sedulous doesn't add any more content; it refers to diligent and again describes the word with perseverance. From this point (checking dictionaries only), I don't see any difference at all. I continued with a corpora search. From : Diligent is most used in combination with work, effort, research, study but also student, people.  She's a diligent student. His diligent research identified the value of ...  Assiduous is also most used with work, effort, research but not with student, people. Merriam-Webster's Learner's Dictionary entry on  lists student as example though.  He's assiduous in his work. With assiduous attention to detail ...  Sedulous is most used, um, to little results.  has even less content. Merriam-Webster's example is, once again, a student. So, diligent is used most often, followed by assiduous and sedulous is quite rare. All words are formal. All words seem to be usable as an attribute to a person (e.g., student) but also specifying the intense care and effort on work, e.g., a research. I don't see any significant difference in these words, besides frequency. When is a student diligent, assiduous or sedulous? And when is a research diligent, assiduous or sedulous? Or simply: What are the subtle distinctions which aren't represented by dictionaries? I'm trying to figure out how to send all information that is normally identified in the /var/adm/message file on a Solaris system to a remote system. Comma after introductory words, phrases, clauses: unacceptable, obligatory or optional? What happens when many neurons have same weights? Does it make any sense to have two (or more) neurons in a neural network with the same weights? (intuitively it makes no sense, since all the neurons would behave the same way).   Please consider both the input and hidden layers. What if the weights are equal 0? I hope it is alright to ask something like this here, I am having trouble keeping up with all the special cases and my book is being kind of vague.  I know how to do the standard method of finding diagonal matrices, but I know that triangular matrices are special and my book makes a connection, but it is hard to tell what it is.  Thanks.