I've just started learning Java, when trying to compile the below source code using "Javac" I am getting the following error:  "C:\Java>javac 99Bottles.java  99Bottles.java:1: error:  expected  public class 99Bottles { //open Class "99Bottles"  Can't seem to figure out if this is a syntax error or if i'm missing something? Any advice would be greatly appreciated, thanks    public class 99Bottles { //open Class "99Bottles"     public static void main (String[] args) { //Open main method         int Beernum = 99; //delcate intergar called "Beernum" with value of 99         String word = "bottles"; //delcare the string "word" with a value of "bottles"          System.out.println(Beernum + " " + word + "of beer on the walL");  //prints         System.out.println(Beernum + " " + word + "of beer"); //prints         System.out.println("you take one down"); //prints         System.out.println("you pass it around"); //prints          Beernum = Beernum - 1; //subtract 1 from the value of "Beernum"          if (Beernum &gt; 0) { //Check if Beernum is greater than 0                 System.out.println(Beernum + " " + "of beer on the wall"); //prints         } else { //if the if statement is not true run this                 System.out.println("no more bottles of beer on the wall"); //prints             }              } }
What characters are valid in a Java class name? What other rules govern Java class names (for instance, Java class names cannot begin with a number)?
Example of a series! Give an example of a convergent series $$\sum_{n=1}^{\infty}a_n$$ such that the series $$\sum_{n=1}^{\infty}a_{3n}$$ is divergent..  I cannot find find any kind of series... I am also be very thankful if you find a divergent series (changing the term convergent)... Video editing. Audio and Video strip have different length How do I make exponential equation with points?  Here are my points:  x = 0, y = 0 x = 1, y = 4.75000 x = 2, y = 9.26250 x = 3, y = 13.54937 x = 4, y = 17.62191   this is same as   x = 0, y = 0 x = 1, y = (0 + 5) * 0.95  x = 2, y = ((5 * 0.95) + 5) * 0.95 x = 3, y = (((5 * 0.95) + 5) * 0.95 + 5)) * 0.95 x = 4, y = ((((5 * 0.95) + 5) * 0.95 + 5)) * 0.95 + 5) ) 0.95   as x value increase by 1, y value is added by 5 and multiplied by 0.95 i tried to make an equation for this but i couldn't  also i tried to use natural exponential but the initial value is 0 so it didn't work  please help me What happens to spirits/souls of other creatues than Elves and Men after their death? I am asked to fill the genotypes in the spaces provided but looks like I am aving a little bit of trouble. can anyone help? thanks in advance! Let's say I write a mine.service file. Then I use systemctl enable mine.service.  If I later decide to edit mine.service, do I have to tell systemd that mine.service was changed? If so, how do I do that? Why would a JavaScript variable start with a dollar sign? I quite often see JavaScript with variables that start with a dollar sign. When/why would you choose to prefix a variable in this way?  (I'm not asking about $('p.foo') syntax that you see in jQuery and others, but normal variables like $name and $order) Suppose $A$ and $B$ are similar matrices. Show that $A$ and $B$ have the same eigenvalues with the same geometric multiplicities.      Similar matrices: Suppose $A$ and $B$ are $n\times n$ matrices over $\mathbb R$ or $\mathbb C$. We say $A$ and $B$ are similar, or that $A$ is similar to $B$, if there exists a matrix $P$ such that $B = P^{-1}AP$. I am comfortable with the different sizes of infinities and Cantor's "diagonal argument" to prove that the set of all subsets of an infinite set has cardinality strictly greater than the set itself. So if we have a set $\Omega$ and $|\Omega| = \aleph_i$, then (assuming continuum hypothesis) the cardinality of $2^{\Omega}$ is $|2^{\Omega}| = \aleph_{i+1} &gt; \aleph_i$ and we have $\aleph_{i+1} = 2^{\aleph_i}$.  I am fine with these argument.  What I don't understand is why should there be a smallest $\infty$? Is there a proof (or) an axiom that there exists a smallest $\infty$ and that this is what we address as "countably infinite"? or to rephrase the question "why can't I find a set whose power set gives us $\mathbb{N}$"?  The reason why I am asking this question is in "some sense" $\aleph_i = \log_2(\aleph_{i+1})$. I do not completely understand why this process should stop when $\aleph_i = \aleph_0$.  (Though coming to think about it I can feel that if I take an infinite set with $\log_2 \aleph_0$ elements I can still put it in one-to-one correspondence with the Natural number set. So Is $\log_2 \aleph_0 = \aleph_0$ (or) am I just confused? If $n \rightarrow \infty$, then $2^n \rightarrow \infty$ faster while $\log (n) \rightarrow \infty$ slower and $\log (\log (n)) \rightarrow \infty$ even slower and $\log(\log(\log (n))) \rightarrow \infty$ even "more" slower and so on).  Is there a clean (and relatively elementary) way to explain this to me?  (I am totally fine if you direct me to some paper (or) webpage. I tried googling but could not find an answer to my question) Fraleigh(7ed) Theorem33.12. Let $p$ be a prime and let $n\in\mathbb{Z}^+$. If $E$ and $E&#39;$ are fields of order $p^n$, then $E \simeq E&#39;$.   Proof in the text: Both $E$ and $E&#39;$ have $\mathbb{Z}_p$ as prime field, up to isomorphism. By Corollary 33.6(A finite extension $E$ of a finite field $F$ is a simple extension of $F$), $E$ is a simple extension of $\mathbb{Z}_p$ of degree $n$, so there exists an irreducible polynomial $f(x)$ of degree $n$ in $\mathbb{Z}_p[x]$ such that $E\simeq \mathbb{Z}_p[x]/ \langle f(x) \rangle$. Because the elements of $E$ are zeros of $x^{p^n}-x$, *we see that $f(x)$ is a factor of $x^{p^n}-x$ in $\mathbb{Z}_p[x]$*. Because $E&#39;$ also consists of zeros of  $x^{p^n}-x$, we see that $E&#39;$ also contains zeros of irreducible $f(x)$ in $\mathbb{Z}_p[x]$. Thus, because $E&#39;$ also contains exactly $p^n$ elements, $E&#39;$ is also isomorphic to $E\simeq \mathbb{Z}_p[x]/\langle f(x) \rangle$.  I don't know why $f(x)$ divides $x^{p^n}-x$. $E$ has a zero $\alpha$ of $f(x)$, but it doesn't need to have all the zeros of $f(x)$. So $f(x)=(x-\alpha)g(x)$ in $E[x]$ and $g(x)$ need not be splitted into linear factors. How can $f(x)$ divide $x^{p^n}-x$? My roommate put a hunk of beef roast in the slow-cooker for a good 6 hours.  It's a fairly large sized slow-cooker, at least 8 quarts.  The meat was cooked through but very chewy, and I never remember my mom having that issue with a slow-cooker.  My roommate tends to put only enough water to get halfway up the side of the roast, and always uses a slow-cooker 'bag' (another thing my mom never did).  What advice can I offer them to get a better outcome? How does Ascending work? The next upgrade I am likely to get is "ASCENSION" for Amenhotep.  The mouseover text on the ability says it restarts the game and gives a single hero soul.  Does anything else cross over (heroes, gold, achievements, etc.)?  When would be the best time to Ascend?  Should I wait until I unlock all the heroes or buy all their abilities?  I'm on level 85 now (not yet beat the boss), should I wait until a specific level? Show that for $\eta > 0$, $\alpha_\eta=-\infty$ and for the Cauchy problem $z'=x-z^2,z(0)=\eta$ the saturated solution is defined up to $+\infty$. We consider the differential equation $y'=x+y^2$ and for any $\eta \geq 0$ we denote by $\phi_\eta:(\alpha_\eta,\beta_\eta)\rightarrow\mathbb{R}$ the unique saturated solution of the Cauchy Problem $y'=x+y^2$, $y(0)=\eta$. I am required to do the change of variable $z(x)=y(-x)$ and I succeded here, obtaining $y'(-x)=y^2(-x)-x$ and so $z'(x)=x-z^2(x)$, then I was required to represent the $0-isocline$ and it was also simple as I obtained a parabolla and also I was required to write the equation of the tangent in the point $(0,\eta)$ which was also pretty simple as I obtained $\phi'_\eta(0)=\eta^2$ and the equation of the tangent is $y=\eta+\eta^{2}x$. Now, I am required to find $\phi^{(5)}_0(0)$( that $5$ indicates the number of differentiations), which puzzles me as I don't know the form of the solution and if it can be found out and also I am told to show that $\frac{1}{\eta}\geq\beta_\eta$ What I did not prove after the first edit : and that for $\eta &gt; 0$, $\alpha_\eta=-\infty$ and for the Cauchy problem $z'=x-z^2,z(0)=\eta$ the saturated solution is defined up to $+\infty$. At this last ones I am lost. Any help, please? Edit: I have passed beyond finding $\phi^{(5)}_0(0)$ and I think I did show that $\frac{1}{\eta}\geq\beta_\eta$, now it remains to prove the last questions. How do I perform a Perl substitution on a string while keeping the original? In Perl, what is a good way to perform a replacement on a string using a regular expression and store the value in a different variable, without changing the original?  I usually just copy the string to a new variable then bind it to the s/// regex that does the replacement on the new string, but I was wondering if there is a better way to do this?  $newstring = $oldstring; $newstring =~ s/foo/bar/g; I have installed Ubuntu 12.04-64 bit on my Lenovo IdeaPad laptop, and the wired Ethernet (LAN) connection doesn't work.  Running the lspci -vv | grep Atheros command from the terminal shows me I have the AR8161 Gigabit Ethernet controller:  02:00.0 Ethernet controller: Atheros Communications Inc. AR8161 Gigabit Ethernet (rev 08)   This looks like a new product whose drivers are not built into Ubuntu.  How do I install drivers to get the AR8161 working? Why does HDD activity slow the whole System down (on Windows 7)? If I copy a large amount of data from on drive to another (physical) drive my whole system is running slow.  I am using Windows 7 64bit version on an Intel Core 2 Duo 3 GHz.  This is the situation:   Very fast copying between two SATA disks.  Resource Monitor shows 80MB/s read, 70MB/s writes and 150MB/s total The total CPU load is about 3% There is plenty (>2GB) of free physical RAM left All partitions have enough (>10gb, >10%) of free space left and show low fragmentation Anti-Virus software is not active   This is the problem: No matter what I want to do while copying, it takes forever. Even tasks that do not need a lot of disk access (as they should work from RAM only), are extremely slow. The moment I stop the copying process, all the unfinished tasks finish at once. For example trying to open a new browser windows or explorer window will not work. If the copying is stopped 5 explorer windows popup at once.  My question is: why? What resource is exhausted, if CPU and memory are idle? And what part of my computer hardware I need to upgrade to get better behavior? Also read Psycogeek's comment for further questions in this direction.  If your answer is, that everything needs HDD Access, which is blocked by such an activity, then my question is: Is there a way to copy something on your system without rendering it unusable until its done? (which can be hours, if >500g have to be copied). Convert XML/HTML Entities into Unicode String in Python How do I center a container in my HTML/CSS? BASH script to set environment variables not working I've written the following script to set some environment variables when needed.  #!/bin/sh export BASE=/home/develop/trees echo $BASE export PATH=$PATH:$BASE echo $PATH   Below the command and the results I can see on my terminal: the script runs, but the variables are not set at the end.  ~$: ./script.sh /home/develop/trees /bin:......:/home/develop/trees ~$: echo $BASE  ~$:    What's wrong? Thanks in advance. Mirko Is zero input impedance good or possible when considering impedance matching? For RF applications, we are usually considering of impedance matching to choose load impedance as the conjugate of the source input impedance for the maximum transferred power. But how about design the source having zero input impedance? Is it even possible or good? A naive thought is that all the power will be on the load if so. I might think it is true for DC case and for amplifier design to have a small output impedance and big input impedance. I lack the knowledge to find the missed chain to put all the knowledge together. How do you think? Thanks!