Ubuntu says no LTS release available, trying to go 18.04 to 20.04.1
Should I be offered the option to upgrade to 18.04.1?
Proof of the First Isomorphism Theorem for Groups OS: Ubuntu 12.04  Accidentally deleted dpkg. Now, packages can't be installed. So, needs an dpkg installer which installs packages. Disabling submit-button until the user has completed the form How do you think about disabling the submit-button until the user has completed the form or the required fields?   I find similar questions here on ux.se and somebody answered that the user will think that the form is broken or not immediately realize whats going on.  I think hiding is not that good but a disabling (e.g. grayscale, opacity, ...) plus a short text in the button would improve usability because the user realise that he still has to fill out something.  Is there anybody with experience or examples besides the usual error-messages/validation after submitting? Convert NSDate to NSString Suppose I have a dataframe consisting of six time series. In this dataframe, some observations are missing, meaning at some timepoints all time series contain a NA-value. In R, one possible imputation package that can be used to impute time series data is Amelia. However, this package does not work for observations that are completely missing. Are there other ways to impute my data? For what it's worth, the amount of missing observations is less than 20% of all observations. When the loop is the figure shown below will be rotated in clockwise direction the the slip ring connected to the red segment of the loop will give us the positive voltage and the slip ring connected to the black segment of the loop will give us negative voltage according to the Flemings right hand rule.  What if the loop is rotated in counter clockwise direction ? Will the slip rings provide us the same polarities which they were giving when the loop was moving clockwise ?  Plus  The voltage from the loop is given by the equation.  V(t) = Vmaximum * sin (theta)  Where theta is the positive angle the red segment makes in the clockwise direction or in counter clockwise direction from this position ? How can I skip every even item in the enumerate environment without having to continually type \setcounter{enumi}{5}? I am still learning to program macros, so I spologize if this is a ridiculously easy question.   Just to be clear, I would like something like   1. *Something.* 3. *Somthing else.* 5. *A third something.*  ...As opposed to   1. Something.  2. A second something.  3. A tertiary Something. Will it be possible to create apps/games in Java SE or Java ME on new Ubuntu phones? Ubuntu 13.04 on Mac Mini 6,2 ethernet port Broadcom NetXtreme BCM57766 not detected The said network adapter is not recognized in 13.04. In 12.04 and 12.10 I had used the driver proposed from broadcom download site, configured as dkms package it was always updated.  On the 3.8.x kernels this provided kernel driver from broadcom does not compile anymore - and the distribution provided tg3 drivers does not recognize the ethernet adapter - even though it is a newer version.  ~$ modinfo /lib/modules/3.8.0-19 generic/kernel/drivers/net/ethernet/broadcom/tg3.ko | grep -i version version:        3.128 srcversion:     D737202366709FE01964BF0 vermagic:       3.8.0-19-generic SMP mod_unload modversions    Here the working version on kernel 3.5.x using dkms  ~$ modinfo /lib/modules/3.5.0-25-generic/updates/dkms/tg3.ko | grep version version:        3.124c srcversion:     D01ED9A7BF2C3956E212A63 vermagic:       3.5.0-25-generic SMP mod_unload modversions    The Network card:  ~$ lspci -nn | grep 0200 01:00.0 Ethernet controller [0200]: Broadcom Corporation NetXtreme BCM57766 Gigabit Ethernet PCIe [14e4:1686] (rev 01)   As found on the i7 Mac Mini 6,2.  Anyone knows where I can get a kernel that recognizes that ethernet device ? That chip is supported somehow ... And - the 3.8.x kernel is way better on the HD4000 chip - reason I use it.  Note - to get the WiFi working, just make sure you load the b43 driver at boot (/etc/modules). At least then you have Network connectivity. When & How often do 4e Monster powers recharge? Suppose that $f : \mathbb{C} \to \mathbb{C}$ is entire. Let $\Omega = \{ z : \frac{1}{2} &lt; |z| &lt; 2\}$. Furthermore, suppose that $ \mathcal{F} = \{f(kz) : k \in \mathbb{C}\}$ is a normal family of analytic functions defined on $\Omega$; the family $\mathcal{F}$ is normal on $\Omega$ iff each sequence from $\mathcal{F}$ has a subsequence converging uniformly on compact subsets of $\Omega$. Prove that $f$ is a polynomial.  I'm studying for my qualifying exam in complex analysis, and this question appears on an old exam. Usually, when I want to show that some entire $f$ is a polynomial, I just try to show that there exists some $N$ so that $f^{(k)}(0) = 0$, all $k \ge N$, but I'm having trouble getting that strategy to work here. I've been looking at the sequence $f(\frac{z}{n})$ trying to make something work, but have not had any success.   I would prefer to receive a hint or two, and then I'll try to post my own solution. Thanks in advance! Will running a large query on a secondary database in an availability group affect transaction performance in the primary database? I need to provide real-time, or almost real-time, data for SSRS and Tableau reporting. I don't want the production OLTP system to be negatively impacted by long running queries. Will running a large query on a secondary database in an availability group affect transaction performance in the primary database? Let $M,N$ be $n \times n$ square matrices over an algebraically closed field with the properties that the trace of both matrices coincides along with all powers of the matrix. More specifically, suppose that $\mathrm{Tr}(M^k) = \mathrm{Tr}(N^k)$ for all $1\leq k \leq n$. The following questions about eigenvalues is then natural and I was thinking it would be an application of Cayley-Hamilton but I am having trouble writing out a proof.  How do we show that $M$ and $N$ have the same eigenvalues?  Added (because this question is now target of many duplicates, it should state its hypotheses properly). Assume that all the mentioned values of $k$ are nonzero in the field considered; in other words either the field is of characteristic $0$, or else its prime characteristic $p$ satisfies $p&gt;n$. Erdős-Straus conjecture The  (ESC), states that for every natural number $n \geq 2$, there exists a set of natural numbers $a, b, c$ , such that the following equation is satisfied:  $$\frac{4}{n}=\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\tag{1}$$  The basic approach to solving this problem outlined by Mordell [Ref1] is described below  By defining $t$ and $m$ as positive integers greater than zero and $q$ a positive integer greater than one we can observe that  a) There is always a solution for even $n$, since if $n=2^qt$ we have the trivial solution $$\frac{4}{4t}=\frac{1}{t}$$  In the remaining case $n=2(2t+1)$, a solution in the form of two Egyptian fractions can always be found  e.g. $$\frac{4}{2(2t+1)}=\frac{2}{2t+1}=\frac{1}{t+1}+\frac{1}{(t+1)(2t+1)}$$  b) If $(1)$ is a solution for some particular prime $n$ then all composite numbers $mn$ divisible by $n$ are also solutions, thus  $$\frac{4}{mn}=\frac{1}{ma}+\frac{1}{mb}+\frac{1}{mc}$$  will also be a solution. This means that we can simplify the analysis to the cases where $n$ is a prime greater than 2.  Using Mordell's approach we have just shown that we only need to consider the cases where $n$ is prime and where $n \equiv 1 \pmod{2} \;\;[meaning \;\;n=2t+1]$  The argument continues...  Mordell goes on to show in turn that the search can be reduced further to the cases when $$n \equiv 1 \pmod{4} \;\;[meaning \;numbers \;\;n=4t+1]$$ $$n \equiv 1 \pmod{8} \;\;[meaning \;numbers \;\;n=8t+1]$$ $$n \equiv 1 \pmod{3} \;\;[meaning \;numbers \;\;n=3t+1]$$ $$n \equiv 1,2,4 \pmod{7} \;\;[meaning \;numbers \;\;n=7t+1,n=7t+2 \;or\;n=7t+4 ]$$ $$n \equiv 1,4 \pmod{5}  \;\;[meaning \;numbers \;\; n=5t+1 \;or\;n=5t+4]$$  Assembling these results together, Mordell showed that the conjecture can be proved in this context except for the cases when $$n \equiv 1,11^2,13^2,17^2,19^2,23^2 \pmod{840}$$  Mordell stated that since the first prime meeting this condition is 1009, this is proof that the conjecture holds for $n&lt;1009$.  This basic approach can be pursued further. Other workers have shown that the conjecture holds for much higher values of $n$ using similar methods as can be seen on the above Wikipedia page.   Note that other intermediate results can be constructed from the above congruence's, e.g. $n \equiv 1 \pmod{24}$.  The question is:  Are there any other elementary approaches to solving this problem than the one outlined by Mordell (and described above)?  [Ref1] Louis J. Mordell (1969) Diophantine Equations, Academic Press, London, pp. 287-290. If $\sum_{n=1}^\infty \frac{1}{a_n}$ converges, must $\sum_{n=1}^\infty \frac{n}{a_1 + \dots + a_n}$ converge? Suppose $\sum_{n=1}^\infty \frac{1}{a_n} = A$ is summable, with $a_n &gt; 0,$ $n = 1,2,3,\cdots.$ How can we prove that $\sum_{n=1}^\infty \frac{n}{a_1 + \dots + a_n}$ is also summable?  This question came from a problem-solving seminar, but I'm quite stuck without a push in the right direction. I tried a few things, including Cauchy-Schwarz (which says $\sum_{n=1}^\infty \frac{n}{a_1 + \dots + a_n} &lt; \sum_{n=1}^\infty \frac{A}{n}$) and also the idea of assuming the latter series diverges and attempting to deduce the divergence of the former series from that, using facts such as $\sum a_n = \infty \implies \sum \frac{a_n}{a_1 + \cdots + a_n} = \infty$. Nothing has worked so far. Is it acceptable to change the vid column of a term programmatically in the database? I am having a problem with Windows 7. When I boot up, the CPU jumps to 100% execution for about 10-15 minutes. During this time, it is really slow, and if I play any music, the songs play slowly and sound distorted.  I tried to scan my computer with different antivirus programs, I used Spybot, HijackThis, and CCleaner, but I didn’t find anything of note.  I watched the process list in Task Manager and saw that there are two processes that are to blame. There are two copies of svchost.exe, one using ~48% CPU, the second (under the Network Service account) using ~37%. For the first 15 minutes, the CPU runs at about 70-80%, then eventually drops to 30-40%.  I don’t know what to do. I could not find a way to stop the services, and if I try to kill them, sometimes the system crashes. How do I automatically remap buttons on my mouse at startup? An  can be identified by its  together with isolating intervals with rational bounds for its real and imaginary parts. The degree of an algebraic number is the  of its minimal polynomial. There are known algorithms that allow to easily compute sum and product of algebraic numbers in this representation, raise them to a rational power, extract real and imaginary parts, compare them, or evaluate them numerically to an arbitrary precision.  Is there an efficient algorithm that given an algebraic number $\alpha$ in this representation can decide if $\alpha$ can be represented as a sum or product of algebraic numbers of smaller degree? Find all integer solutions to $x^2+y^2+z^2=2xyz$