Difference between modelAttribute and commandName
Difference between modelAttribute and commandName attributes in form tag in spring?
Why can't we see light travelling from point A to B? Let's say we have a cloud of dust which is a lightyear across and someone shoots a beam of light from point A to B , why it is not possible for an observer far far away to see the light while it travels through the cloud at the speed of light? How can I upgrade Mac OS without the administrator password? I recently received an old iMac secondhand.  I have no way to reach the original owner. I am trying to upgrade the OS software, but the prompts demand the administrator's name (which is auto-filled) and password (which I do not have).  I understand why these security features are in place, but is there any way in the world for me to access Admin. privileges without the password? Random point uniform on a sphere If $X=(x,y,z)$ is a random point uniform on the unit sphere in $\mathbb{R}^3$,  Are the  coordinates $x$, $y$, $z$ uniform in interval $(-1,1)$? Is there an official Marvel Cinematic Universe viewing order? A simple stupid question that I should already know the answer to:  Is this true: $\left|z^5\right| = \left|z\right|^5$ where z is a complex number with a non-zero imaginary component.  Thanks in advance. Convert a Cannondale SM1000 (about 1991 model) to disk brakes I've got an older, about 1991, model Cannondale SM1000 mountain bike purchased new.  Would it be worth it to convert to disk brakes and if so what would be the process? How do I get horizontal lines to the left and right of a heading in Microsoft word? In Word 2007 I want to put a heading in the center of a line with a horizontal line to the left and to the right of the text.  The line must not cross through the text. I have tried using autoshapes and lines - but then the lines move each time I press Enter or &larr; Backspace and I have to put them in place again manually.  At Borders and Shading there is an "Insert horizontal line" option, but this gives me a solid line from the left to the right of the page and I cannot insert text anywhere on it or in it.    The final product should look something like this:     -------------------------  Heading ------------------------- Recovering user files with a Live CD For some reason I can't boot my system. I get an error akin to Operating System Not Found.   I tried bootrepair, and that didn't work. So then I decided I would just save my personal files, wipe everything, and reinstall.   But in the live session, when I go to the /home directory, my username folder isn't there, instead it goes to the Live CD's desktop and other directories. Is there some other error occurring? Is there a way to recover the files? filter the file type with the file upload control Is it possible to backup individual files with Deja Dup? In the Deja Dup preferences, it is possible to select certain folders to backup and certain folders to exclude.  I would like to be able to backup individual files in my Home folder (Such as .vimrc and .bashrc), but I don't see any way to do this.   So my question is, is it possible to either     Select individual files (instead of whole folders) to backup, or backup my Home folder, but exclude all subfolders? Radius of convergence of a sum of power series I have  two series  $\displaystyle\sum_{n=1}^{\infty} a_n x^{n}$   $\displaystyle\sum_{n=1}^{\infty} b_n x^{n}$  with radius of convergence $2$ and $3$ respectively.  How can I find the radius of convergence for the following?     $\displaystyle\sum_{n=1}^{\infty} (a_n +b_n)x^{n}$   Can anyone help me? Force pagebreak after every sentence/paragraph Is there a way to force a pagebreak after every sentence or paragraph?  This may seem like an odd thing to do, but for catching typos and just general editing I find it much easier to look at a sentence or paragraph in isolation so that I am not tempted to skip ahead.  Currently, I just zoom in so I can only see a few word at a time, but this is not a perfect solution. It looks like Ubuntu 11.04 will come with  by default. I do like them, but I don't like the current mix of scrollbar types as many applications don't yet use those overlay scrollbars.  Is there a way to disable overlay scrollbars (without removing the overlay-scrollbar package)? Nested Radical of Ramanujan I think I have sort of a proof of the following nested radical expression due to Ramanujan for $x\ge 0$.     $$\large x+1=\sqrt{1+x\sqrt{1+(x+1)\sqrt{1+(x+2)\sqrt{1+\cdots}}}}$$ for $ x\ge -1$   I just want to know if my proof is okay or there is a flaw, and if there is one I request to give some suggestions to eliminate them. Thank you. The proof is the following:  Proof: Let us define $$ a_n(x)=\underbrace{\sqrt{1+x\sqrt{1+(x+1)\sqrt{1+(x+2)\sqrt{1+\cdots}}}}}_{n \ \mbox{terms}}$$ for $x\ge 0$ so that $$ a_1(x)=\sqrt{1+x},\ a_2(x)=\sqrt{1+x\sqrt{1+(x+1)}},\ a_3(x)=\cdots$$    and so on. Since $x\ge 0$ each one of the $a_n$ is defined (I am taking only the positive square root). Also, we note that $$a_{n+1}^2(x)=1+xa_{n}(x+1)$$  Now, we note that $\{a_n(x)\}$ is an increasing sequence and that $$a_n(x)&lt;x+1$$ $\forall n\ge 1$, this is easy to prove by induction as below:  For $n=1$, $a_1(x)=\sqrt{1+x}&lt;1+x$ since $x\ge 0\Rightarrow 1+x\ge 1$. SO it is true for $n=1$. Similarly, the truth can be proved for $n&gt;1$.  Then $a_n(x)$ converges to $$l(x)=\sup_{n}a_n(x)\le x+1$$ Now I make the following claim:  Claim: $l(x)=x+1\quad \forall i\ge 0$  Proof: Fix $x$. Let $l(x)&lt;x+1$. Then, $l(x)=x+1-\epsilon$ for some $\epsilon&gt;0$. Now, I claim that there must be a $n$ such that $$x+1-a_n(x)&lt;\epsilon$$, and if that is true then $$a_n(x)&gt;x+1-\epsilon=l(x)$$ which is a contradiction since $$l(x)=\sup_{n}a_n(x)$$ and then it implies that $$l(x)=x+1$$ To prove my claim it requires $$x+1-a_n(x) &lt;  \epsilon$$ Now, \begin{align} x+1-a_n(x) = &amp; x+1-\sqrt{1+xa_{n-1}(x+1)} \\ \ =&amp; \frac{(x+1)^2-({1+xa_{n-1}(x+1)})}{x+1+\sqrt{1+xa_{n-1}(x+1)} } \\ \ =&amp; x\frac{(x+1)+1-a_{n-1}(x+1)}{x+1+\sqrt{1+xa_{n-1}(x+1)} } \\ \ &lt;&amp; \frac{x}{x+2}((x+1)+1-a_{n-1}(x+1))\\ \ &lt;&amp; \frac{x}{x+2}\cdot\frac{x+1}{x+3}((x+2)+1-a_{n-2}(x+2))\\ \ &lt;&amp; \frac{x}{x+n-1}\cdot \frac{x+1}{x+n} ((x+n-1)+1-a_{1}(x+n-1))\\ \ &lt;&amp; \frac{x}{x+n-1}\cdot \frac{x+1}{x+n}(x+n-\sqrt{x+n})\\ \ &lt;&amp; \frac{x(x+1)}{x+n-1} \end{align}  Now, if one is able to find $n$ such that $$\frac{x(x+1)}{x+n-1}&lt;\epsilon \Rightarrow x&lt; \frac{-(1-\epsilon)+\sqrt{(1-\epsilon)^2+4\epsilon(n-1)}}{2}$$ then we're done.   Now from the upper bound it seems that there always exists some $n$ that satisfies this requirement. Hence the claim is proved. Variance of dot product When reading a proof I came across the following step:  $$\operatorname{Var}(x^Ty) = x^T\operatorname{Var}(y)x$$ $x$ and $y$ are column vectors. How can you derive this? Close vote review audit is broken - displays "on hold" while reviewing I just reviewed this:    But while reviewing, it already displays the "put on hold as not a real question" section, and it asked:     Should this question be closed as: ?   So as it stands, the audits are broken, since we already know that the question is "on hold" while reviewing, and it is incredibly hard to miss the huge grey box at the bottom.  Another with screenshot: Can I legally downgrade from Win 7 64 bits to Win 7 32 bits? Possible Duplicate:          Tired of the unstable Win 7 64bit I got when I purchased my laptop (it was impossible to find a powerful laptop with Win 7 32 bits).  Can I legally downgrade from Win 7 64 bits to Win 7 32 bits? The key/activation will work?    Details: Everybody comments about the stability of Win 64.  Well, I made a mistake. Is not that Win 64 is unstable (it never crashed). It just works very poor. It feels choppy. Compiling a large program (on an old AMD desktop PC) takes 1.5 seconds on Win 32. The same program compiles on Win 64 in 4-5 seconds in this new and "powerful" laptop. All programs are less responsive. Disable drag and drop option for multiple file uploader These are the screenshots of multiple file uploader from the same SharePoint 2010 site. Some users are seeing the first and some are seeing the second one. Is it possible to disable the second view(drag and drop) by editing upload.aspx in the layouts folder?      Thank you Other word for person who does something to others but does'nt like it done to them This is a duplicate question but has still not been answered for me. I'm so close to the exact word - I know there is one out there - but the closest word I can find is a hypocrite --     a person who claims to have certain moral principles or beliefs but behaves in a way that shows they are not sincere.    The word I'm looking for is a person who does not claim things, but does thing to another and they consider it wrong or immoral to have done to them. Can't get armature to move mesh!