Are these two infinite groups isomorphic?
how to prove $G_1$ and $G_2$ aren't isomorphic?
GCSE: Find the number of person that will go to a party It is a general concept that horizontal forces can only influence physical quantities along horizontal direction; similarly vertical force can produce acceleration etc. only along vertical direction. This is the same concept that helps us study projectile motion as a combination of two independent motions. If this relation is universally true, how come, then friction depend on a force which normal to it? Our iPad is locked and we're not sure of the Apple ID / iCloud password I currently trying to join two rigged (and animated) models, which both has separate meshes, separate bones and separate animations. The first mesh is the horse while the second mesh is human:   So I am interested to join human model onto horse model to make a rider:   I think the best way would be to make horse as a parent and human as a child during the join process. In that case I would like that all horse animations (there are 3 of them - idle, walk and run) would remain as they are, while I can lose human animations, as I will need different ones for it. I was also thinking to make human root bone as a child of one horse back bones, that when horse moves up and down it would move entire human mesh together. It would be also good to keep the same weights that human bones would not start deforming horse mesh and vice versa.  I tried to use Ctrl+J by selecting various combinations between bones and meshes in object mode, however, I noticed that it messes up scaling and rotation of the child object. So I was wondering how it would be possible to properly join these models to create a rider? How do I create a shortcut for a script, and run it as a .desktop file? I have installed Teamspeak onto my Ubuntu 15.10 system. Teamspeak requires a script to be ran in-order to start. How can I create a symbolic link that is a .desktop so I can open the .desktop file, and have it run the script? I have looked at a few methods, but they all seem like hotfixes. Is there a proper way to do this? Let $G$ pe a $p$ group. I have to show that         the number of nonnormal subgroups is divisible by $p$       the number of subgroups differs from the number of normal subgroups by a power of $p$.   Are there any theorem that can help me to prove this ? We have discussed the Sylow theorems but I don't know how to apply them - if those are the theorems I need. (Does this theorem also hold for infinite groups $G$ ?) Working with objects created with Activator.CreateInstance How does a cell phone charger work? I have studied that there is a transformer which steps down the ac voltage after then bridge rectifier to convert into ac to dc and then given to filter, this is what I have learnt in books, but when I open a mobile charger I couldn't figure it out how it actually works? Apt-get 403 Forbidden, but accessible in the browser How to send a header using a HTTP request through a cURL call? I wish to send a header to my Apache server on a Linux box.  How can I achieve this via a cURL call? The main doubt one can have about mirrorless is, I think that they do not provide ttl viewfinder. Is this a big disadvantage? In what way is it worst (or best) than classical reflex system?  What are the others advantages and disadvantages of a mirrorless compared to a reflex?  Have mirrorless a chance to replace reflex (at least for non pros) in the future? In the PGF/TikZ manual, sometimes I see the option right of=somenode instead of right=of somenode. They look very similar, but the effects are different.  The distance between nodes positioned with the latter option is boundary-to-boundary, as stated in the manual. However, with the first option, it seems that the distance is shorter. I couldn't find any explanation of the first option in the manual.  My question is: what is the difference between the two options? Is there any explanation in the manual that I missed? What is the term for a factorial type operation, but with summation instead of products? Several ways to prove that $\sum\limits^\infty_{n=1}\left(1-\frac1{\sqrt{n}}\right)^n$ converges List all the directories under the current one I'm trying to find the longest consecutive set of composite numbers Hello and I'm quite new to Math SE.  I am trying to find the largest consecutive sequence of composite numbers. The largest I know is:  $$90, 91, 92, 93, 94, 95, 96$$  I can't make this series any longer because $97$ is prime unfortunately.  I can however, see a certain relation, if suppose we take the numbers like (let $a_1, a_2, a_3,...,a_n$denote digits and not multiplication):  $$a_1a_2a_3...a_n1,\ a_1a_2a_3...a_n2,\ a_1a_2a_3...a_n3,\ a_1a_2a_3...a_n4,\ a_1a_2a_3...a_n5,\ a_1a_2a_3...a_n6,\ a_1a_2a_3...a_n7,\ a_1a_2a_3...a_n8,\ a_1a_2a_3...a_n9,\ a_1a_2a_3...(a_n+1)0$$  The entire list of consecutive natural numbers I showed above can be made composite if:   The number formed by digits $a_1a_2a_3...a_n$ should be a multiple of 3 The numbers $a_1a_2a_3...a_n1$ and $a_1a_2a_3...a_n7$ should be composite numbers   If I didn't clearly convey what I'm trying to say, I mean like, say I want the two numbers (eg: ($121$, $127$) or ($151$, $157$) or ($181$, $187$)) to be both composite.  I'm still quite not equipped with enough knowledge to identify if a random large number is prime or not, so I believe you guys at Math SE can help me out. While I'm aware of  it does not quite answer my question. I have a simple sentence:     If any of the devices was not switched off, do something.   Is there supposed to be was or were? I was thinking about was since it could be rephrased as:     If any one of the devices was not switched off, do something.   But maybe that does not make any sense at all. Also, this is for a technical documentation where more formal language is preferred, not sure if that makes any difference. I want to know, if this bug is fixed, because all previous versions of Ubuntu didn't work for me. So I just want to know, should i leave Windows 10 and go for Ubuntu 17.10. Thanks! Do internal forces cause change in velocity? Searching a virtual printer, that sends emails I need a software, that emulates a printer, converts the printed documents to PDF/TIFF and send it via eMail to a specified address (for windows).  The virtual printer / PDF conversion is possible with a lot of PDF-converters. But I need a software, which is also able to directly mail me these PDFs. It's always the same mailaddress, and I have an SMTP server.  Any suggestions?