We installed ubuntu linux in windows 10 machine. However, we are not getting dual booting option to run ubuntu after rebooting the laptop. After rebooting, windows 10 always shows up, never ubuntu linux. Please help us to fix this problem.
I installed Ubuntu on a Dell XPS 13 laptop that had Windows 10 preinstalled on it. I installed it from a USB flash drive on a partition. When I boot my computer I can only boot into Windows 10 and Ubuntu is nowhere to be seen.  If I boot into my USB then I can see that Ubuntu is installed, but I can't get to it from the BIOS boot menu.
How do I know if food left at room temperature is still safe to eat? Uniform random variable as sum of two random variables Taken from :  Show that it cannot be the case that $U=X+Y$ where $U$ is uniformly distributed on [0,1] and $X$ and $Y$ are independent and identically distributed. You should not assume that X and Y are continuous variables.  A simple proof by contradiction suffices for the case where $X$, $Y$ are assumed discrete by arguing that it always possible to find a $u$ and $u'$ such that $P(U\leq u+u') \geq P(U\leq u)$ while $P(X+Y \leq u) = P(X+Y \leq u+u')$.  However this proof does not extend to $X,Y$ being absolutely continuous or singular continuous. Hints/Comments/Critique? Python, Unicode, and the Windows console When I try to print a Unicode string in a Windows console, I get an error . UnicodeEncodeError: 'charmap' codec can't encode character .... I assume this is because the Windows console does not accept Unicode-only characters. What's the best way around this? Is there any way I can make Python automatically print a ? instead of failing in this situation? Edit:  I'm using Python 2.5.  Note: @LasseV.Karlsen answer with the checkmark is sort of outdated (from 2008). Please use the solutions/answers/suggestions below with care!!  is more relevant as of today (6 Jan 2016). Which video editor can I use to make clips to upload? I am looking for an easy video editor for Ubuntu 12.04. My needs are simple: make clips and upload them on sites (cut segments from a video file with frame to frame precision, convert into common formats, resize the file).  Can anyone suggest one? Where does the energy for osmosis come from? A thought experiment:     A U-shaped tube with semi-permeable membrane at the base. The tube is completely thermally isolated from its surroundings. The liquid (solvent) is at some temperature $T$. When solute is added to one side of the tube the fluid level on that side rises until the increased pressure due to gravity ($\rho gh$) equals the osmotic pressure.   If I understand correctly, osmotic pressure could be used to do work (i.e. lift a weight as the solvent level in one side of U-shaped tube increases). Where does this energy come from? I guess it must be from the internal energy of the fluid.  At this point has the temperature of the fluid decreased?? If so, has it decreased by exactly the work done against gravity divided by the specific heat of the fluid? What does the quantitative treatment of this problem look like? Alternative to Photoshop or Paint.NET I've come across a small issue which occurs when a question has been closed but the question itself or one of its answers are being edited.  Steps to reproduce:   Visit a closed question. (even closed years ago)   In a different tab or browser, edit the question or one of its answers. "an edit has been made to this post; click to load" message will appear above the edited post in the first tab/browser, click it. The .question-status div becomes hidden, which includes the closed notice below a question and, for a duplicate-closed question, the list of duplicates above the question body. This gives the appearance that the question is no longer closed (until you refresh).   Some screenshots:                I know it isn't common/important but it did confuse me when looking at a particularly bad question - I thought it had been reopened.   Is this an intentional feature? If so, what was the thinking behind it?    Another example  Before    After Last activity on question shows modified by user who did not ask or answer .       The  has no sign of the user sharth The  also does not have any sign of related activity   I would like to know why the user's name is associated with the question. At least why their display name shows up as having modified the question timeline activity.  Possible reason that I can think of is that, .  Is this the reason?  Is there a way (for normal users), to look for such details, other than looking at the user activity and the question's revision history. Computing $\int_{-\infty}^\infty \frac{\sin x}{x} \mathrm{d}x$ with residue calculus This refers back to $\int_{-\infty}^\infty \frac{\sin x}{x} \mathrm{d}x = \frac\pi2$ already posted. How do I arrive at $\frac\pi2$ using the residue theorem? I'm at the following point: $$\int \frac{e^{iz}}{z} - \int \frac{e^{iz}}{z},$$ and I would appreciate any help. Overriding the final destination of the OAuth2.0 flow from a custom OAuth2.0 Auth provider Background:  I have created a custom Auth. Provider in Salesforce to reach out to an authorization server that isn't on the default list of Provider Types. I used  as a good starting point to extend the Auth.AuthProviderPluginClass. Once appropriately added to my org, it then became an option on the list of Provider Types. I was able to create an Auth. Provider using that new provider type and it works to initiate the OAuth2.0 flow. I am appropriately able to get the access token and refresh token from the authorization server.  The Problem:  As it currently stands, we will have users click on a button that will send them to the provided "OAuth-Only Initialization URL" link that was generated when I created the actual Auth. Provider record. The trick is that when the OAuth2.0 flow is completed, the user is redirected back to the Salesforce Setup Home page, and I don't see a good way in the documentation to override the final destination to be something else (like a success page or something).  Question:  Does anyone know of a way to override the final destination of the OAuth2.0 flow from a custom OAuth2.0 Auth provider?    UPDATE: I tried using the startUrl (and also tried retUrl for good measure) as query params, but doing so didn't change the behavior after the OAuth2.0 flow finished.  Meaning, both of the following URLs gave me the same final destination as not having any query params at all:  https://&lt;scratch org random url&gt;.my.salesforce.com/services/auth/oauth/MyCustomAuthProvider?retUrl=lightning%2Fpage%2Fhome   https://&lt;scratch org random url&gt;.my.salesforce.com/services/auth/oauth/MyCustomAuthProvider?startUrl=lightning%2Fpage%2Fhome     Another Update: This WORKED:  https:/&lt;scratch org random url&gt;.my.salesforce.com/services/auth/oauth/MyCustomAuthProvider?startURL=%2Flightning%2Fn%2FCustomPage   Apparently, it was important to add the leading /, (of course, url encoded to be %2F) and %2Flightning%2Fpage%2Fhome gets interpreted as the setup home and sends you there.    (Parallel posted to Salesforce Dev Forum: ) Question: If $c\neq 1$ is an $n^{th}$ root of unity then, $1+c+...+c^{n-1} = 0$  Attempt: So I have established that I need to show that $$\sum^{n-1}_{k=0} e^{\frac{i2k\pi}{n}}=\frac{1-e^{\frac{ik2\pi}{n}}}{1-e^{\frac{i2\pi}{n}}} =0$$ by use of the sum of geometric series'. My issue is proceeding further to show that this is indeed true. What are the regulations for transporting medication abroad? This is in reference to medications, both prescription and non-prescription, not illicit drugs. Since the legality may vary on country, let's say a round trip from the US to Singapore, as an example.  When travelling with prescription medication, I am aware that you are supposed to bring your prescription with you. What about over-the-counter medication, such as Tylenol/aspirin? How about medication which is restricted or prescription-only in one country, yet available OTC in another (think Viagra)? List.Add seems to be duplicating entries. What's wrong? Why is my USB drive showing corrupted data when plugged as an internal SATA drive? I have a 3TB Seagate Backup Plus Desktop USB 3.0 drive, which works fine when in its enclosure, but when I get it off its enclosure and directly plug it as an internal SATA drive, it's just not properly recognized (it works again when used in the enclosure). My systems’s motherboard is an , which has two SATA 6.0 Gb/s and four SATA 3.0 Gb/s ports.  When used as an internal SATA drive Windows 7 asks if I want to format the drive, as if it didn’t have a proper filesystem, and if I use the DISKMGMT.MSC tool (typing that in the start menu) I get completely wrong information about the drive.  It says the drive has 3 partitions (349,31GB of RAW data and two unassigned partitions of 1698,68GB and 746,52GB). This information is plain wrong, since the drive, when used in the USB enclosure, works as a single NTFS partition (2794,52GB). How come it’s shown as 3 partitions without filesystem when connected through SATA?!  Is Seagate using some proprietary way of storing the data when using the drive in its provided USB 3.0 enclosure? I didn’t use any kind of encryption. I just plugged the drive with USB 3.0 and started using it straight away, since it apparently came pre-formatted with an NTFS filesystem. Are there philosophers who examined the reasons for believing in the existence of other people? While I am familiar with Descartes and the oft-quoted idea, I think therefore I am, I am not familiar with any philosophy that actively sought to rationalize that anybody else exists.  Are there philosophers who analyzed this question? Or is it taken for granted that it is (im)possible for anybody to validate their own existence to somebody else? When should I add another answer? I have been member of SO for 4 months. I have a question regarding some functionality. Whenever I give an answer to a question, there is functionality given Add Another Answer. I can comment on my answer at any time and also able to edit answer. Then   Why this functionality given on SO to add another answer?  When should I add another answer?  Why there is requirement of multiple answers? What is limit of adding answers to single question? Open an app on startup/after booting I need to force a selected application to start up each time my Android-based device is (re)started.  Is there anything I can use (configuration setting, external application etc.) to accomplish this task? Or is this kind of behavior limited to home screen managers only? Number theorems with chapter number I use declaretheoremstyle to define a theorem environment, and print a list of theorems in the end of my document:  \documentclass[12pt]{book} \usepackage[english]{babel} \usepackage[margin=2cm]{geometry}% just for the example \usepackage{xcolor} \usepackage{amsthm} \usepackage{thmtools} \usepackage{mdframed} \usepackage{etoolbox}  \declaretheoremstyle[   spaceabove=6pt, spacebelow=6pt,   headfont=\normalfont\bfseries,   postheadspace=1em,   notefont=\bfseries,   notebraces={(}{)},   bodyfont=\itshape,   shaded={bgcolor=yellow!20} ]{thmstyle}  \declaretheorem[style=thmstyle,name=Theorem]{theorem}  \begin{document}  \begin{theorem}[Somebody] ... \end{theorem}  \begin{theorem} ... \end{theorem}  \renewcommand{\listtheoremname}{List of Theorems} \addcontentsline{toc}{section}{\listtheoremname} \listoftheorems[ignoreall,show=theorem]  \end{document}   The theorems are numbered from the beginning to the end of the book, and from 1:    However, I would like to number the theorems with chapter number (like Figures or Tables), for instance, 1.1 (the first theorem in Chapter 1), 1.2 (the first theorem in Chapter 2)...  Does anyone know how to do it? If $|G| = pq$,  $p,q$ primes, $p \gt q, q \nmid p-1 $, then how do I prove $G$ is cyclic without using Sylow's theorems? What does "official Ubuntu flavour" mean? What kind of support do they receive from Canonical or/and Ubuntu community? Who decides a distro should become official flavour? What privileges do "official flavours" have over unofficial derivatives of Ubuntu like Linux Mint, Elementary OS, Deepin OS,etc.?