Proving that $\sum\limits_{n=1}^∞\frac{a_n}{s_n^2}$ converges
Suppose $a_n>0$ and $\sum_{n=1}^{\infty}{a_n}$ diverges. Determine convergence of $\sum_{n=1}^{\infty}{\frac{a_n}{s_n^2}}$, where $s_n=\sum^n a_n$.
When should you use struct and not class in C#? My conceptual model is that structs are used in times when the item is merely a collection of value types.  A way to logically hold them all together into a cohesive whole.  I came across these rules :   A struct should represent a single value. A struct should have a memory footprint less than 16 bytes. A struct should not be changed after creation.   Do these rules work? What does a struct mean semantically? This is probably a silly question but I need some help. I opened a file that I've been working on for about a month in the new 2.8 version of Blender. However when I tried to reopen the file in version 2.79, the scene is completely empty. Here is where the problem lies for me, I accidentally saved over the original file save while in version 2.8 . Please help. Thanks! How to find correctly the .bib file? Gauss's Law with Moving Charges Prove that $Au\cdot v = u\cdot A^Tv$ Let A be an $n$ x $n$ matrix and let $u$,$v$ $\in$ $\mathbb{R^n}$. Prove that $$Au\cdot v = u\cdot A^Tv$$  I tried using the fact that $A^Tu=A\cdot u$. However, I cannot seem to get to this result. Could anyone please help me out? some more examples:   "And she gave me that aren't-I-just-gorgeous smile." "The I-did-it-my-way approach." "A from-this-day-forward-I-have-no-son scene." Was Yoda fully sane on Dagobah? Our (and Luke's) original impression of Yoda is by no means flattering. He looks like a crazy hungry green thing that unfortunately has the ability to speak. Yoda digs through Luke's stuff, eats Luke's food, and, obsessed with that awesome little flashlight, ends up stealing it. (He even goes so far as to fight with Artoo over it.)  So was Yoda slowly losing it during all those years as a hermit?  Perhaps going from fighting battles and conversing with others on a daily basis to living in total isolation with no one to speak with would play a part in that? Or could Yoda have been faking his apparent insanity for some reason? (If so, what is mentioned reason?) Present perfect for past action with present effect Suppose f(m,n) is a double sequence in $\mathbb R$. Under what condition do we have $\lim\limits_{n\to\infty}\sum\limits_{m=1}^\infty f(m,n)=\sum\limits_{m=1}^\infty \lim\limits_{n\to\infty} f(m,n)$? Thanks! Is there an easy way to attach source in Eclipse? I'm a big fan of the way Visual Studio will give you the comment documentation / parameter names when completing code that you have written and ALSO code that you are referencing (various libraries/assemblies).  Is there an easy way to get inline javadoc/parameter names in Eclipse when doing code complete or hovering over methods? Via plugin? Via some setting? It's extremely annoying to use a lot of libraries (as happens often in Java) and then have to go to the website or local javadoc location to lookup information when you have it in the source jars right there! After the recent "Look and Feel" Apple vs Samsung lawsuits, I've been wondering to what extent this might affect websites/webapps that offer functionality similar to other existing sites.  So what exactly would one have to be wary of to make sure they don't step on the toes of a big corporation?  I could see carbon copying a companies website/app (especially if it's a very distinctive product) being a bad practice that could get you some backlash, especially blatantly ripping off iconic terminology, but how similar is too similar?  Does the ten-foot rule apply to the web?     “If a reasonable person could not, at ten feet, tell the difference between two competitive products, then there was cause to believe an infringement was occurring.”   Or is there a separate legal precedent associated with the web?  And then where does feel, which is essentially the common term for UX, come in.  Can you patent the way a website "feels", as in the flow, organization and functionality associated.  I understand that you can't patent basic elements like radio buttons, but what about the layout and look of a large number of those elements used in combination to complete a certain action/s?    I know that is still a bit of a Sword of Damocles for online retailers.  Where is the line drawn for website/webapp copyright infringement?  Or is there even a line drawn yet? “Airplane Mode” in OS X. Alternative command for `rfkill`? Mac OS X doesn't recognize rfkill from its terminal, and I am looking for an alternative command that has similar functionality (toggling "Airplane Mode").  NOTE: I don't wish to open an .app to toggle. I'd like to execute the command from command line or within script in Bash (or equivalents).    By "Airplane Mode", I meant to borrow the term from iOS support page . I would like to disable all incoming/outgoing network communications from my system. Single question thread with multiple questions, some duplicates I've recently run into many questions where to author asks several related questions in one post, many of them asked before.   I'm wondering what out policy is on such questions:   Should I vote-close them as being not constructive? Should I vote-close them as duplicates? Should I leave them be? Or even suggest an answer?    - Each of the questions: Waiting for an AJAX request with selenium, and headless browsing in selenium have been asked here before, but he asked both in one.  I've done my best to search for similar questions here in meta but I was unable to find any, reading appreciated. Today I upgraded to the Creators Update by running setup from the ISO mounted locally. When I got back to my computer I opened Task Manager and saw my memory usage was a lot higher than it was previously (it's now almost 6GB memory usage at idle after logging in instead of 2-3GB with the previous Windows build) - the processes tab revealed that there were upwards of 60 different instances of svchost.exe running. This 6GB figure is just for process memory - not including memory used for caching or "standby".  I ran tasklist /svc to get a listing of which services were in which processes and it lists almost every svchost.exe instance as only having one running service contained within (with the exception of a handful of instances that are running a few system services).  Here's  my output:  Image Name                     PID Services ========================= ======== ============================================ System Idle Process              0 N/A System                           4 N/A smss.exe                       440 N/A csrss.exe                      612 N/A wininit.exe                    700 N/A csrss.exe                      708 N/A services.exe                   776 N/A lsass.exe                      784 KeyIso, Netlogon, SamSs, VaultSvc svchost.exe                    888 PlugPlay svchost.exe                    908 BrokerInfrastructure, DcomLaunch, Power,                                    SystemEventsBroker fontdrvhost.exe                936 N/A svchost.exe                   1000 RpcEptMapper, RpcSs svchost.exe                    104 LSM winlogon.exe                   544 N/A fontdrvhost.exe                420 N/A svchost.exe                   1072 DeviceInstall dwm.exe                       1136 N/A svchost.exe                   1164 BFE, CoreMessagingRegistrar, MpsSvc svchost.exe                   1424 lmhosts svchost.exe                   1432 W32Time svchost.exe                   1440 nsi svchost.exe                   1448 wudfsvc svchost.exe                   1528 hidserv svchost.exe                   1628 Dhcp svchost.exe                   1716 Dnscache svchost.exe                   1748 EventLog WUDFHost.exe                  1792 N/A svchost.exe                   1908 TimeBrokerSvc svchost.exe                   1952 NlaSvc NVDisplay.Container.exe       1968 NVDisplay.ContainerLocalSystem svchost.exe                   1324 Themes svchost.exe                   1596 ProfSvc svchost.exe                   1944 EventSystem svchost.exe                   1052 netprofm svchost.exe                   2116 StateRepository svchost.exe                   2256 SENS svchost.exe                   2296 AudioEndpointBuilder svchost.exe                   2304 FontCache (etc)...   I know you can configure individual services to run in their own instance of svc with the sc config &lt;serviceName&gt; type= own command, but to my knowledge I've never run this command.  I took a quick look at Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and it looks like the Type key values for most of these services is missing the flag bit at 0x10 which controls if a service runs in its own svchost.exe instance or not. I wonder what could have effected this change.  Has anyone else observed this behaviour before or after installing Windows 10 Creators Update? If it is a default configuration change, will it have any implications on system performance or stability?  I suspect it will increase system stability because if a service crashes it won't bring down other services - but this comes at a massive cost of RAM - but I've never experienced a service crashing on me - or at least ever noticed it (instead the worst problem I've had is with wuauserv consuming 100% CPU for hours on end - and that's not a problem process isolation will solve).  (I just noticed: they finally added an address bar to the Registry Editor!) Difference in output between SAS's proc genmod and R's glm I'm trying to replicate a model fitted in SAS in R but the fit I'm getting gives me slightly different coefficients and standard errors.  Data:  testdata &lt;- data.frame(matrix(c("f","Test", 1.75,   16, 0,  16, 0,  1,  1, "m",    "Test", 1.75,   15, 1,  16, 6.25,   1,  0, "f",    "Test", 2.75,   4,  12, 16, 75, 1,  1, "m",    "Test", 2.75,   9,  6,  15, 40, 1,  0, "f",    "WHO",  1.75,   15, 1,  16, 6.25,   0,  1, "m",    "WHO",  1.75,   14, 2,  16, 12.5,   0,  0, "f",    "WHO",  2.75,   2,  13, 15, 86.6667,    0,  1, "m",    "WHO",  2.75,   3,  13, 16, 81.25,  0,  0 ), ncol=9, byrow=TRUE)) names(testdata) &lt;- c("sex", "vaccine", "dose", "not_p", "para", "n", "pct",                       "vacnum", "sexno")   SAS:  proc genmod data=model_data; class sex; model para/n  = dose sex vacnum    /dist=bin    link=logit   type3; run;  Analysis Of Maximum Likelihood Parameter Estimates  Parameter   DF Estimate Std Error Wald 95% Conf Lim Wald Chi-Square Pr &gt; ChiSq  Intercept   1 -9.4020   1.6220    -12.5810  -6.2230  33.60           &lt;.0001  dose        1  3.9208   0.6460      2.6546   5.1870  36.83           &lt;.0001  sex f       1  0.5574   0.5184     -0.4587   1.5735   1.16           0.2823  sex m       0  0.0000   0.0000      0.0000   0.0000    .              .  vacnum      1 -1.3221   0.5483     -2.3967  -0.2475   5.81           0.0159  Scale       0  1.0000   0.0000      1.0000   1.0000        R:  testdata$sexno &lt;- as.factor(testdata$sexno)     a &lt;- contr.treatment(2, base = 1, contrasts = TRUE)  contrasts(testdata$sexno) &lt;- a  fitreduced &lt;- glm(para/n ~ dose + as.factor(sex) + vacnum,                    family=quasibinomial(link="logit"), data=testdata)  coef(summary(fitreduced))                    Estimate Std. Error   t value    Pr(&gt;|t|) (Intercept)     -9.4013750  1.7613982 -5.337450 0.005935450 dose             3.9173794  0.7001133  5.595351 0.005007179 as.factor(sex)1  0.5704671  0.5568436  1.024466 0.363525300 vacnum          -1.3336100  0.5887552 -2.265135 0.086189704   I believe I have the right contrasts to give me a type III SS but there is a small discrepency in values, have a missed something here? Prove that, $\binom{3n}{r}=\binom{3n-1}{r} + \binom{3n-1}{r-1}$ Reading through my textbook I came across the following problem and I am looking for some help solving it.  Prove that,  $$\binom{3n}{r}=\binom{3n-1}{r} + \binom{3n-1}{r-1}$$  In a previous problem I solved the following but I wasn't sure how to use it to prove the question above. Prove,  $$\binom{n}{r}=\binom{n}{n-r}$$  Solution:  left Side,  $$\binom{n}{r}=\frac{n!}{(n-r)!r!}$$  right side,  $$\binom{n}{n-r}=\frac{n!}{(n-(n-r))!(n-r)!} = \frac{n!}{(n-r)!r!}$$  Therefore completing the proof,  but how do I solve my first question? thanks! optimality of the Carnot cycle Make HttpURLConnection load web pages with images Retail boxed Steam activated games: can they be resold? I recently purchased retail boxed versions of   Dead Island (which is awesome) Warhammer 40k: Space Marine (not so much)   I finished both games and I was thinking of reselling them or giving them to a friend to play. However, these are both Steam activated games that had a required Steam registration code I had to enter -- and validate on Steam -- as part of the installation.  If I give these games to a friend or resell them, will they even work? Is the registration code single use and tied to a single person / computer / Steam account? I want to install Win Xp on my Ideapad Z 570 laptop but i always get blue screen with message with some drive related problem which asks me to run CHKDSK command. I tried with that but no luck. Is there any way i can install Win Xp with SP 2 ?  Edit: i searched across the sites and came to know there could be some Compatibility problems, and i could fix it by setting HDD mode to IDE; will it solve the problem?