is it even possible to connect two USB-C displays to one MacBook Pro 15" 2018?  Seems like MacOS intentionally shuts down one of them. I'm a bit puzzled why..
How do I find out the number, type, resolution &amp; refresh rate of additional monitors I can attach to my MacBook or MacBook Pro?  This is an attempt at a canonical QA, as per the Meta QA -   to try prevent the myriad "same but different" questions we get on every possible combination of computers, cable &amp; monitors There are perfectly good resources out there that Ask Different should not have to duplicate the efforts of.
Convergence of Ratio Test implies Convergence of the Root Test In Elias Stein and Rami Shakarchi's Complex Analysis textbook, we have the following exercise:     Show that if $\{a_n\}_{n=0}^\infty$ is a sequence of complex numbers such that $$\lim_{n\to\infty}\frac{|a_{n+1}|}{|a_n|}=L,$$ then $$\lim_{n\to\infty}|a_n|^{1/n}=L.$$    I've been trying to prove this with no luck. The only thing I've thought of doing is $$\lim_{n\to\infty}\left(\frac{|a_{n+1}|^n}{|a_n|^n}\right)^{1/n},$$but this hasn't lead me anywhere except dead ends. Will someone provide a hint for me about how to proceed? Thanks!  Minor update: I don't know if it's helpful yet, but I know we can write the limit as $$\lim_{n\to\infty}\left(\frac{|a_{n+1}a_n\cdots a_0|}{|a_n\cdots a_0|}\cdot\frac{1}{|a_n|}\right).$$This reminds me a lot of the geometric mean, which even has the exponents I'm trying to get... Java Command line arguments I am trying to detect whether the 'a' was entered as the first string argument. How can I find all files that do NOT contain a text string? What concise command can I use to find all files that do NOT contain a text string?  I tried this (using -v to invert grep's parameters) with no luck:  find . -exec grep -v -l shared.php {} \;   Someone said this would work:  find . ! -exec grep -l shared.php {} \;   But it does not seem to work for me.   has this example:  find ./logs -size +1c  &gt; t._tmp while read filename do      grep -q "Process Complete" $filename      if [ $? -ne 0 ] ; then              echo $filename      fi done &lt; t._tmp rm -f t_tmp   But that's cumbersome and not at all concise.  ps: I know that grep -L * will do this, but how can I use the find command in combination with grep to excluded files is what I really want to know.  pss: Also I'm not sure how to have grep include subdirectories with the grep -L * syntax, but I still want to know how to use it with find :) 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? Proof that $\suṃ̣_{k=1}^{n}k {n \choose k}$ for $n \in \mathbb N$ is equal to $n2^{n-1}$.  As a hint I got that $k {n \choose k} = n {n-1\choose k-1} $.  I tried solving this by induction but, in the inductive step I'm not arriving to the correct result. Why energy curves spacetime? This  explains how energy curves spacetime. But I would like to know why energy curves spacetime, is there something like particle interaction that produce this result? NOTE: I am not interested in calling /secur/logout.jsp since it ends all the active salesforce sessions.  I am developing a web application that is registered on salesforce as a connected app, so I am using salesforce credentials to authorize the user.  Application is developed in REST API and the communication with salesforce is happening in restful manner.   Auth url:   Authorization:  Method 1: If there is no salesforce session active, The user is taken to salesforce login page, where he enters his salesforce details to be authorized and after which he is taken to home page of my web application.  Method 2: If there is already a salesforce session active in another tab, the user is directly authorized and is taken to home page of my web application.  Now I am trying to implement logout button for my application, such that the following scenarios are covered,  Scene 1: The user is authorized using method1, and the user press the logout. Upon trying to logback the user is prompted for credentials.  Scene 2:  The user is authorized using method2, and the user should use logout to logout of the web application (not from active sessions). Upon login, the user should be again able to login using method2.  Can someone help me on how to implement the logout button such that it covers scenario 1 &amp; 2.  Thanks in advance. Why is my Mac constantly trying to connect to another server? After logging on, I see this dialog box pop up. Whenever I dismiss it, it reappears 30 seconds later. (Stealing focus at the same time! Grrrr!)    "Slate" is my old iMac, which is sitting on the desk next to me, turned off. How can I stop my new Mac from constantly trying to connect to my old one? Both are running 10.7.1. I honestly have no idea how to approach this question. I have done easier questions eg. show $gcd(a,b)lcm(a,b)=ab$ by letting $a=Alcm(a,b)$ and $b=Blcm(a,b)$ and then using the fact that $A$ and $B$ are coprime. However this approach only works in two variables. Any help with the question in the title would be greatly appreciated, as well as the thought process behind the answer so that I can approach similar problems. I have an iMac, connected to the Internet via Ethernet, and an iPhone 4. I would like to share the iMac's Internet connection to my iPhone via the USB Cable (because my wife dreams of a wifi-less household).  I've set up Internet Sharing, specifying "sharing from: Ethernet  via: USB IPhone", but when I test, the iPhone cannot connect to the Internet. Is there something I need to activate on the iPhone?   iMac, mac os x version: Mountain Lion, 10.8.4 iPhone 4, IOS Version: 6.1 What can I use instead of the arrow operator, `->`? Best way to implement keyboard shortcuts in a Windows Forms application? Although elements like &lt;div&gt;s normally grow to fit their contents, using the float property can cause a startling problem for CSS newbies: If floated elements have non-floated parent elements, the parent will collapse. For example:   &lt;div&gt;   &lt;div style="float: left;"&gt;Div 1&lt;/div&gt;   &lt;div style="float: left;"&gt;Div 2&lt;/div&gt; &lt;/div&gt;    The parent div in this example will not expand to contain its floated children - it will appear to have height: 0. How do you solve this problem? I would like to create an exhaustive list of solutions here. If you're aware of cross-browser compatibility issues, please point them out. Solution 1 Float the parent.   &lt;div style="float: left;"&gt;   &lt;div style="float: left;"&gt;Div 1&lt;/div&gt;   &lt;div style="float: left;"&gt;Div 2&lt;/div&gt; &lt;/div&gt;    Pros: Semantic code. Cons: You may not always want the parent floated. Even if you do, do you float the parents' parent, and so on? Must you float every ancestor element? Solution 2 Give the parent an explicit height.   &lt;div style="height: 300px;"&gt;   &lt;div style="float: left;"&gt;Div 1&lt;/div&gt;   &lt;div style="float: left;"&gt;Div 2&lt;/div&gt; &lt;/div&gt;    Pros: Semantic code. Cons: Not flexible - if the content changes or the browser is resized, the layout will break. Solution 3 Append a &quot;spacer&quot; element inside the parent element, like this:   &lt;div&gt;   &lt;div style="float: left;"&gt;Div 1&lt;/div&gt;   &lt;div style="float: left;"&gt;Div 2&lt;/div&gt;   &lt;div class="spacer" style="clear: both;"&gt;&lt;/div&gt; &lt;/div&gt;    Pros: Straightforward to code. Cons: Not semantic; the spacer div exists only as a layout hack. Solution 4 Set parent to overflow: auto.   &lt;div style="overflow: auto;"&gt;   &lt;div style="float: left;"&gt;Div 1&lt;/div&gt;   &lt;div style="float: left;"&gt;Div 2&lt;/div&gt; &lt;/div&gt;    Pros: Doesn't require extra div. Cons: Seems like a hack - that's not the overflow property's stated purpose. Comments? Other suggestions? Convert a string/integer to superscript in C# A specific file on our production servers is being modified at apparently random times which do not appear to correlate with any log activity.  We can't figure out what program is doing it, and there are many suspects.  How can I find the culprit?  It is always the same file, at the same path, but on different servers and at different times.  The boxes are managed by , but the puppet logs show no activity at the time the file is modified.  What kernel hook, tool, or technique could help us find what process is modifying this file?    lsof is unsuitible for this, because the file is being opened, modified and closed very quickly.  Any solution that relies upon polling (such as running lsof often) is no good.      OS: Debian testing Kernels: Linux, 2.6.32 through 3.9, both 32 and 64-bit. When does System.gc() do something? C# Regular Expressions with \Uxxxxxxxx characters in the pattern Qt signaling across threads, one is GUI thread? Why is the method executed immediately when I use setTimeout? Print on terminal and into file simultaneously?