My wife and I often watch videos on the plane together, we used to use our iPad together with a headphone splitter so we could watch a movie together - but then we lost the splitter. Anyway, I'm thinking about getting bluetooth headphones for work and am wondering: Is it possible, for instance, to watch a video / movie on an iPhone (we each have an iPhone 6) or iPad with both a wired headphone plugged into the 1/8" headphone jack, and also have a second set connected via Bluetooth?
Me and my friends want to listen to music together. Two of us have Bluetooth Headphones (Beats Solo2 Wireless, Beats Studio Wireless) and one has a wired headset. Is there any way to use all three of these together?
Given that the sequence $(v,Av,A^2v,...,A^nv)$ is linearly dependent (1), $A_{n \times n}$, over $\mathbb{F^n}$ prove that scalars $c_0,c_1,..,c_n$ exist (such that not all of them are zeroes) such that the matrix $M=c_0I+c_1A+..+c_nA^n$ is singular.    First I'm not sure how (*) can be used here exactly. We can say that the sequence $(c_0I,c_1A,..,c_nA^n)$ resembles the sequence (1) where $v=I$. But here we have scalar $c_i$ so it's not exactly the same sequence.   Maybe I could say that the sequence $(c_0I,c_1A,..,c_nA^n)$ is linearly dependent because it has $n+1$ elements while over $dim\mathbb{F^n}=n$ $\quad$(2).  Intuitively I understand that suppose we sum all the matrices $c_iA^i$ and then in the last sum operation we get to some $c_jA^j$ and if it's a linear combination of other matrices then we can have such a $c_j$ that: $$ c_oI+\sum_{i=1}^{n-1} c_iA^i+c_jA^j=0 $$ But I don't think this is enough to prove. How do I create a reflective white material? I'm pretty new to this and this is my first question here, any help would be greatly appreciated.  So basically what I want to achieve is a floor material as seen in this photo...    ...the reflections are very crisp but dim.  With a glossy shader I get the following results:    First picture: reflections are blurry  Second picture: roughness of the material looks right but reflection is bright red  Third picture: If tinted in any other color than white, it seems to produce the result I want. Reflection is sharp and gets tinted blue. What I need is the reflection to be tinted white.  Thanks for any help. broadcast receiver for missed call in android Why does parameter expansion with spaces without quotes work inside double brackets "[[" but not inside single brackets "["? Upper bound on the number of charts needed to cover a topological manifold If $M^n$ is a compact topological manifold (not necessarily with additional structure), is there an upper bound on the number of charts needed to cover $M$ ? Does this bound depend on the dimension of $M$ ?  Thanks in advance...  Cheers creating a csv file from two csv files I have two csv files:  sub_compiler.to_csv('sub_compiler.csv') sub_compiler.head()     and   sub_opt = pd.read_csv('sub_opt.csv') sub_opt.head()     and what I would like to do is to create a csv file where I have something of the form   compiler, opt   How could I do this? I need to do this to make a submission.  Thank's in advance.  [EDIT] Thank you for the answers. Now I have obtained :    don't understand why I have the columns called unnamed.   My objective is to get a csv file that contains only the columns compiler and opt. How could I do this? Thank's again.  [EDIT 2] I have solved my problem but if I open the csv file manually, so just click on the file, I have the following:    s it contains only 11 lines, but it contains 3000 lines in jupyter. Is it there something wrong?  [EDIT 3] I tried to to the following:  import pandas as pd  test = pd.read_csv('1495927.csv') test   and I have:    where 1495927.csv is the csv file I have created and that is in the image where I have 11 elements. Determining whether two $k$-chromatic graphs are isomorphic (respecting vertex coloration) Samsung netbook NP300E5A dimming on battery My Samsung netbook NP300E5A screen is continually dimming.  The screen is forty percent dim on battery, but if I plug in the charger, the screen will be normal. I have tried all I know and I could not fix it. What should I do? what am trying to explain  is that the system is dimming like flooricent light  the screen resolution systems are all ok. When I pluging my charge the dimming we stop but when is on battery it look like flashing someone  light when driving Ubuntu 16.04 LTS Virtualbox 5.0.40 ubuntu r 115130  Today after upgrading to kernel 4.13.0-26 guest vbox machines started to crash whole ubuntu. just hard poweroff is working.  If I startup with kernel 4.10.0-42 everything works fine.  what may be the problem ? Run faster than outer turret attacks As the title says, is there any way to run faster than the turret attack (the missile like thing) so that you can arrive spawn before the attack reaches you, and therefore can't kill you? You know, when you have low health, and you are targeted by the turret? Is there any item sets or things like that? Does a bad grade in one course (with otherwise OK record) affect graduate admissions? I'm currently an M. Phil student in Math and I failed a course last semester because I was not able to hand in a home work assignment (which was worth 40% of my grade) on time (I was 30 minutes late).   Apart from that I'd say I'm a fairly decent student, I got an upper second class honours bachelors degree, I have a B+ and A's for all my other courses in my current programme and I'm almost finished with my first paper to be published.   I've however been deeply worried about this failure as it would reflect poorly on my transcript if I were to apply to a Ph.D or another Master's programme.   Will my failing grade affect my chances of getting into a competitive programme or greatly lower my chances of getting a scholarship? How to use enum values in f:selectItem(s) I've been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) ...   What I'm wondering is, at a core level, what does bit-shifting (&lt;&lt;, &gt;&gt;, &gt;&gt;&gt;) do, what problems can it help solve, and what gotchas lurk around the bend? In other words, an absolute beginner's guide to bit shifting in all its goodness. extract the 4th column from a csv file using unix command I have a csv file formatted as below.  "col1","col2","col3","col4" "1","text1","&lt;p&gt;big       html      text&lt;/p&gt; ","4th column" "2","text2","&lt;p&gt;big2       html2      text2&lt;/p&gt; ","4th column2"   I want to extract the 4th column using.  I think that awk is the best tool for this ( let me know if I am wrong). I tried this   awk -F, '{print $4}' myFile.csv    but it fails.  I think because the 3rd column is multiline one.  How can I use awk or any other unix command to extract the 4th column.  I am looking for an efficient solution since my real file is big (> 2GB) How to test apex classes with Pagereference? I'm struggling to test a class with pagereference. Following is the class...  public with sharing class redirectOrderPartner{  public String currentRecordId {get;set;} public orders__c orderId {get;set;}  public redirectOrderPartner(ApexPages.StandardController controller) {      }     Public Pagereference go(){      currentRecordId  = ApexPages.CurrentPage().getparameters().get('orderid');      system.debug('---currentRecordId  ---'+currentRecordId  );     orderId = [select id from orders__c where name =: currentRecordId limit 1];      system.debug('---orderid---'+orderId);      PageReference pageRef = new PageReference('/apex/OrderTrackingClass?id='+orderId.id);     pageRef.setRedirect(true);     return pageRef;    }   }   Following is what I tried....    @isTest  public class redirectOrderPartner_TEST  {             static testMethod void Test(){            Account acc = new Account(Name='ABC Corp.');           insert acc;            orders__c tempOrder = new orders__c(name = '0001234567', account__c = acc.id );           insert tempOrder;            Test.startTest();            PageReference pageRef = Page.redirectOrderPartner;           Test.setCurrentPage(pageRef);            ApexPages.Standardcontroller sc = new ApexPages.Standardcontroller(tempOrder);           ApexPages.currentPage().getParameters().put('Id',tempOrder.name);           PW_redirectOrderPartner ec = new redirectOrderPartner(sc);           ec.go();                                   Test.stopTest();       }   } I get the following error message on testing..     System.QueryException: List has no rows for assignment to SObject   What am I missing? Thanks How do I monitor the computer's CPU, memory, and disk usage in Java? I would like to monitor the following system information in Java:   Current CPU usage** (percent) Available memory* (free/total) Available disk space (free/total)  *Note that I mean overall memory available to the whole system, not just the JVM.   I'm looking for a cross-platform solution (Linux, Mac, and Windows) that doesn't rely on my own code calling external programs or using JNI. Although these are viable options, I would prefer not to maintain OS-specific code myself if someone already has a better solution.  If there's a free library out there that does this in a reliable, cross-platform manner, that would be great (even if it makes external calls or uses native code itself).  Any suggestions are much appreciated.  To clarify, I would like to get the current CPU usage for the whole system, not just the Java process(es).  The SIGAR API provides all the functionality I'm looking for in one package, so it's the best answer to my question so far. However, due it being licensed under the GPL, I cannot use it for my original purpose (a closed source, commercial product). It's possible that Hyperic may license SIGAR for commercial use, but I haven't looked into it. For my GPL projects, I will definitely consider SIGAR in the future.  For my current needs, I'm leaning towards the following:   For CPU usage, OperatingSystemMXBean.getSystemLoadAverage() / OperatingSystemMXBean.getAvailableProcessors() (load average per cpu) For memory, OperatingSystemMXBean.getTotalPhysicalMemorySize() and OperatingSystemMXBean.getFreePhysicalMemorySize() For disk space, File.getTotalSpace() and File.getUsableSpace()   Limitations:  The getSystemLoadAverage() and disk space querying methods are only available under Java 6. Also, some JMX functionality may not be available to all platforms (i.e. it's been reported that getSystemLoadAverage() returns -1 on Windows).  Although originally licensed under GPL, it  to , which can generally be used for closed source, commercial products. What is the value of the series   $\sum\limits_{n=1}^\infty {\frac{1}{10^n-1}}$   and can one find closed forms for the sums   $\sum\limits_{n=1}^N {\frac{1}{10^n-1}}$?   I found that $\sum_{n=1}^N {\frac{1}{10^n-1}} $  =  $\sum_{n=1}^N (\lim_{m\to\infty  }{\frac{10^{-n}-10^{-nm}}{1-10^{-n}}})$  =  $0.111\ldots+0.0101\ldots+\ldots$ but I can't go farther.     The original question is: "Where does the second '1' appear?" How do the Planets and Sun get their initial rotation? Why do Venus and Mercury rotate so slowly compared to other planets?  Why does Venus rotate in a different direction to Mercury, Earth and Mars? There's a problem statement:     For each $m \in \mathbb{N}$, we construct a sequence $m_0$, $m_1$, $m_2,\dots$ denoted $S_m$, recursively via $m_0=m$ and      $$m_{i+1} = m_i + \left\lfloor \sqrt{m_i} \right\rfloor$$      for all $i \ge 0$.   Here, $\lfloor x \rfloor$ is the floor of $x$, the greatest integer less than or equal to $x$.   Hence, we have $\left\lfloor \sqrt{10} \right\rfloor=3$ and $\left\lfloor \sqrt{29} \right\rfloor=5$.      Show that for each positive integer $m$, the sequence $S_m$ contains the square of some integer.   I'm pretty certain that this can be proved with induction. I am just not quite sure what to induct on. Examining examples shows that $S_m$ always results in a perfect square eventually, though I'm not sure how to prove it. How can one motivate the relativistic momentum?