ALSA-Mixer.conf bug!
Persistent Dummy Output
Let $G$ be a group and $H$ be a subgroup of $G$ of index $2$ .Then show that if $a,b\notin H$ then $ab\in H$. Let $G$ be  a group and $H$ be a subgroup of $G$ of index $2$ .Then show that if $a,b\notin H$ then $ab\in H$.   $a,b\notin H\implies aH,bH\neq H\implies $ $aH=bH$  since $H$ has only two distinct left cosets in $G$.  $\implies a^{-1}b\in H$  How to show that $ab\in H$ from here? What is the Fastest a Character Can Move in One Turn? At level 20 with any magic items in the DMG, and any spells, what is the fastest a DnD 5e character could move using their movement?  (i.e., not including teleportation) How do I address unchecked cast warnings? Eclipse is giving me a warning of the following form:     Type safety: Unchecked cast from Object to HashMap   This is from a call to an API that I have no control over which returns Object:  HashMap&lt;String, String&gt; getItems(javax.servlet.http.HttpSession session) {   HashMap&lt;String, String&gt; theHash = (HashMap&lt;String, String&gt;)session.getAttribute("attributeKey");   return theHash; }   I'd like to avoid Eclipse warnings, if possible, since theoretically they indicate at least a potential code problem.  I haven't found a good way to eliminate this one yet, though.  I can extract the single line involved out to a method by itself and add @SuppressWarnings("unchecked") to that method, thus limiting the impact of having a block of code where I ignore warnings.  Any better options?  I don't want to turn these warnings off in Eclipse.  Before I came to the code, it was simpler, but still provoked warnings:  HashMap getItems(javax.servlet.http.HttpSession session) {   HashMap theHash = (HashMap)session.getAttribute("attributeKey");   return theHash; }   Problem was elsewhere when you tried to use the hash you'd get warnings:  HashMap items = getItems(session); items.put("this", "that");  Type safety: The method put(Object, Object) belongs to the raw type HashMap.  References to generic type HashMap&lt;K,V&gt; should be parameterized. Subclassing tuple with multiple __init__ arguments Two identical files; Apache says one is forbidden I've got this one file, favicon.ico. It's actually a large group of nested files, but purely for example, just this one.  If I do cp favicon.ico favicon2.ico, Apache can read the second one just fine.  If I do mv favicon.ico favicon3.ico, Apache throws a 403 on favicon3.ico.  If I su apache, I can read the file as apache.  stat says both files are identical, except for the inode number.  Is there some hidden flag somewhere or something that I'm missing? I've never seen anything like this.  error_log says (13)Permission denied: access to /favicon3.ico denied The verb let means  “allow”, “permit”, “not prevent or forbid”, “pass, go or come”  and it's used with an object and the bare infinitive.         Are you going to let me drive or not?     Don't let him off the hook.     Before we let our children surf the Internet, they have to do their homework.     She lets the cats out before leaving.   He let us into the house.      The full form let us can be used similarly        Let us know as soon as possible.      Please, let us help you.   They will never let us forget.      None of the above can be contracted; however, when let us is used for making a suggestion; giving self-encouragement; expressing a consequence or plea,  it is often contracted to let's      Let's go out   Let's have a party   Let's see what happens   Let's stand together in this emergency   Let's not forget those who sacrificed their lives     Questions   I believe that let + us is the only instance where this type of contraction occurs. Is there an explanation as to why verbs such as (i) give + us, (ii) get + us or (iii) take + us were not similarly contracted? When was the apostrophe used to replace the omitted letter "u" in let us?  What is the origin of let's? Prove there are no other solutions of functional equation $f(x+y) = \frac{f(x)+f(y)}{1-f(x)f(y)}$ Apex:OutputText to Currency Format from String Wrapper is there a way to pass a string to the &lt;apex:outputText&gt; so that it can be formatted as a currency or percent value?  Here's what I have inside a column of my visual force table:  &lt;apex:outputText value="{0, number, currecny}"&gt; &lt;apex:param value="{!row.values[1]}" /&gt; &lt;/apex:outputText   this gives me an error at runtime (when the visual force page loads), which I think may be some kind of type mismatch, where &lt;apex:outputText&gt; is expecting a Decimal or number but I am passing a string.  This is the error at runtime:     The value attribute on  is not in a valid format. It must be a positive number, and of type Number, Date, Time, or Choice.   Thanks Combinatorial proof of summation of $\sum\limits_{k = 0}^n {n \choose k}^2= {2n \choose n}$ cd to previous directory without echo of directory name This  gave me cd - as shorthand to change to my previous directory in Bash. It does have a major problem: it prints the directory it changes to, wasting my screen space, as that directory is then repeated in the prompt on the next line.  I know I can do cd $OLDPWD, also mentioned in that answer, and cd - &gt;/dev/null but that is much more typing.   In the bash man page it says:     ... or if - is the first argument, and the directory change is successful, the absolute path name of the  new  working  directory  is written to the standard output.   How can I make - not to be the first argument? By using any of the cd optional arguments? Any other way to suppress the echo or minimise typing without the need for defining functions/aliases on every machine I work with? How do I effectively defeat the Wall of Flesh? I've been having trouble defeating this monster. Even with lots of buff potions, health potions, high tier armor (Molten), and ranged weapons with plenty of ammo (Minishark), I can't seem to kill this boss.  Worse, when I get it down to about 2000 hp, even if I'm fairly far away, it'll suck me in and continually rise towards the skybox, which doesn't allow me to do anything for some reason.  How do I defeat the Wall of Flesh? What gear should I be using and what kind of potions do I need? Limit distribution of infinite sum of Bernoulli random variables How do you get Mac OS Finder to group folders together when sorting? I have Mac OS 10.7.4 and I'd like Finder to use "Is Folder?" as its first sort criteria, or in other words, group folders before files regardless of the sorting method.  Windows and Linux both do this by default. How is Anti Aliasing Implemented in Ray Tracing? After reading a few articles online I can confidently say I am clueless on how Anti-Aliasing works when using Ray Tracing.  All I understand is that A Single Pixel/Ray is split into 4 sub-pixels and 4 rays rather than 1.  Could somebody please explain how this is done (preferably with code)? Using setminus notation with set elements The "correct" way to write a set without a specific element is as follows: $S \setminus \{s\}$  But in some contexts this is cumbersome to write/type or read, and it detracts from the flow of the writing. Is it acceptable to just use $S \setminus s$?  Edit: By "cumbersome" i mean they look bad when you're trying to inline formulas in LaTeX. Compared to, for example, completing 5 bounties in each of 5 different games. $x^3+x+1$ irreducible over $\mathbb{F}_2$, $\theta$ root, compute powers of $\theta$ Problem statement:     Show that $x^3+x+1$ is irreducible over $\mathbb{F}_2$ and let $\theta$ be a root. Compute the powers of $\theta$ in $\mathbb{F}_2$.   I am having trouble computing the powers of $\theta$. $x^3+x+1$ is irreducible, since any cubic polynomial over a field is reducible if and only if it has a root in the field. Since $\mathbb{F}_2=\{0,1\}$, we see that none of these is a root of $x^3+x+1$.  To compute the powers of $\theta$, note that $\theta^3+\theta+1=0$. Hence $\theta^3=-(\theta+1)$. Is this a good enough answer for $\theta^3$?  To compute $\theta^2$, note that $\theta = -(\theta^3+1)$. Therefore, $$\theta^2=(\theta^3+1)^2 = \theta^6 + 2\theta^3 + 1 = (-\theta-1)^2-2\theta-2+1,$$ which just reduces to $\theta^2$. Any ideas for computing these powers?  Thanks! Why are there scenes that will not render on GPU but will render fine on CPU? I've already tried GPU Rendering and it seem to be twice as fast as the CPU. However I have some situation where tried to render on the GPU, but it doesn't do anything. When I switch to CPU it renders.  I have some fur texture/materials using particle systems. I wonder if that causes the GPU not to render, I'm not really sure. How can I prove that if $\gcd(a, b) = 1$, then $\gcd(ab, c) = \gcd(a, c) \times \gcd(b, c)$?  By eea there exists $ax+by=1$ from $\gcd(a,b)=1$ so a and be are co-primes there also exists $dk=a$ and $dj= b$ where $d=\gcd(a,b)=1$ this is all the information I have gathered from the question but I dont know how to approach and solve it. Can anyone help explain to me how to arrive at the answer? Thanks! I'm considering buying a subscription to Minecraft Realms (on PC) as a gift for somebody I know. Mojang doesn't have a gift option, and I don't want to spoil the surprise, so I was thinking I'd just buy it myself and give them access.   If I do this, will the recipient be able to turn around and invite their own friends? Can I grant them "admin" access to the server?