I want to force caching the installed packages with apt-get install (apt install) in /var/cache/apt. Currently, I found some of them are cached, but most of them are not. I want to cache all of them to install them on another machine by copying these packages without downloading them again from the Internet, especially for large packages which cost a lot of time.
I know that packages installed with apt-get are stored in /var/cache/apt/archives.  I just installed mariadb server in Ubuntu 16.04 with following command:  sudo apt install mariadb-server   When I tried to find packages in /var/cache/apt/archives, there are no packages. Where are they stored if it's not in this directory?
How do I boot from ISO file stored on hard disk? I need to use binary variables (values 0 &amp; 1) in k-means. But k-means only works with continuous variables. I know some people still use these binary variables in k-means ignoring the fact that k-means is only designed for continuous variables. This is unacceptable to me.  Questions:     So what is the statistically / mathematically correct way of using binary variables in k-means / hierarchical clustering? How to implement the solution in SAS / R? For which real values of t does the following system of linear equations:  $$ \left\{  \begin{array}{c} tx_1 + x_2 + x_3 = 1 \\  x_1 + tx_2 + x_3 = 1 \\  x_1 + x_2 + tx_3 = 1 \end{array} \right.  $$  Have:  a) a unique solution?  b) infinitely many solutions?  c) no solutions?  I haven't done linear algebra in almost a year, so I'm really rusty and could use some pushes in the right direction. Multiple Image in Canvas ItemsControl Proving a simple graph is a connected graph Does any proof exist that a simple graph with $n$ vertices such that the least vertex degree is $\geq \frac{n-1}{2}$ is a connected graph? (i.e. does such a proof have a name?) Postfix SMTP banner show multiple hostnames What is the terminology for data aggregated via summed totals versus data aggregated via means? The two types of data differ in that if you decide to decrease the temporal (time) resolution of the first type of data you take the mean of lower the resolutions. With the second you take the sum over the lower resolutions. Here is a concrete example  Gas Used (kWh), Outside Air Temperature (C), Time Resolution (Minutes) 100, 20, 20 140, 22, 20 120, 21, 20   Here the hourly (60 Minute) resolution data is clearly  360, 21, 60   and is found by averaging the temperature and summing up the gas used.  What I really wish to know is what the names for each of these types of data are called. I understand that this question is not the best but it is hard to ask a question about something whose names you do not know. If you have a better way of articulating the question then please go ahead and edit it. Proving that $a \mathbb{Z} \cap b\mathbb{Z} = \operatorname{lcm}(a,b)\mathbb Z$ Given $m \in \mathbb{Z}$, let $m\mathbb{Z}$ denote the set of integer multiples of $m$, i.e. $m\mathbb{Z} := \{mk\mid k \in \mathbb{Z}\}$.   Now let $a,b \in \mathbb{Z}$ with $a,b$ not both $0$. Prove that $a\mathbb{Z} \cap b\mathbb{Z} = \operatorname{lcm}(a,b)\mathbb{Z}$.   I am trying to write a proof for this, but I am unsure of what method to use. Also I am confused by $mk\mid k$, because wouldn't $m=1$ for this to be true. dd aplied to dev USB before connect corrupt /dev/sdX and dont work $\bigodot=?$ for $(\sqrt 2) ^ \sqrt 3 \bigodot (\sqrt 3) ^ \sqrt 2$ where $\bigodot is \lt or \gt$ $\bigodot=?$ $(\sqrt 2) ^ \sqrt 3 \bigodot  (\sqrt 3) ^ \sqrt 2$  where $\bigodot is either \lt or \gt$   In other words, which one is larger $(\sqrt 2) ^ \sqrt 3$ or $(\sqrt 3) ^ \sqrt 2$? The best I could do was ending up with $\sqrt \frac {3}{ 2} = \frac {\ln 3}{\ln 2}$  side question : is there a symbol like encircled $?$ for when what we are trying to find is the correct order symbol like one of $\lt,\leq,=,\geq , \gt $ ?  Hopefully using just juxtopisition of symbols without resorting to real analysis. is it possible to do with precalculs algebra? Can I convert flat bar to drop bars on a hybrid bike Proving $\sqrt{2}+\sqrt[3]{3}$ is algebraic. My site as of right now is a static website. I am planning on having a 'recent blog posts' section on it, with permalink to the main blog post/blog. example:   http://site.com/blog   I was wondering, because of having a recent blog posts section on the homepage, should I just have the entire website powered by WordPress and just add the homepage (and other pages, such as contact) as a word press 'page', and call recent blog posts on it?  If I do it that way, am I still able to have the blog in /blog?  I was also thinking of just adding the whole WordPress files to the /blog directory and call recent blog posts from the static file...  I am new to Wordpress, so I am a bit confessed here.  What is the best option? I found this math "problem" on the internet, and I'm wondering if it has an answer:     Question: If you choose an answer to this question at random, what is the probability that you will be correct?      a. $25\%$      b. $50\%$      c. $0\%$      d. $25\%$   Does this question have a correct answer? Why is there no analog for $\Theta_\text{QCD}$ for the weak interaction? Is this topological term generated? If not, why not? Is this related to the fact that $SU(2)_L$ is broken? Write space with TCPDF into a PDF file A question about the arctangent addition formula. In the arctangent formula, we have that:  $$\arctan{u}+\arctan{v}=\arctan\left(\frac{u+v}{1-uv}\right)$$  however, only for $uv&lt;1$. My question is: where does this condition come from? The situation is obvious for $uv=1$, but why the inequality?  One of the possibilities I considered was as following: the arctangent addition formula is derived from the formula:  $$\tan\left(\alpha+\beta\right)=\frac{\tan{\alpha}+\tan{\beta}}{1-\tan{\alpha}\tan{\beta}}.$$  Hence, if we put $u=\tan{\alpha}$ and $v=\tan{\beta}$ (which we do in order to obtain the arctangent addition formula from the one above), the condition that $uv&lt;1$ would mean $\tan\alpha\tan\beta&lt;1$, which, in turn, would imply (thought I am NOT sure about this), that $-\pi/2&lt;\alpha+\beta&lt;\pi/2$, i.e. that we have to stay in the same period of tangent.  However, even if the above were true, I still do not see why we have to stay in the same period of tangent for the formula for $\tan(\alpha+\beta)$ to hold. I would be thankful for a thorough explanation. When should we use proximity rule in "either/or", and "neither/nor"? I was making this recipe: , which was from the old Lincoln Del, one of my mom's favourite places. I mistakenly doubled the sugar, putting in 1/2 a cup instead of a 1/4 of a cup. Given the 2/3 of a cup ketchup, which was Heinz, the soup turned out way, way too sweet.   Is there any way I can rescue this? Exercise $1.8$ of chapter one in Hartshorne.