How to use the symbols in System`Private`?
How to know the usage of undocumented function like LinearAlgebra`BLAS?
I have recently started using blender and one of the models I'm working on has dark shadows along edges. I started this model from scratch. I can't remember them being there when I first started the model, but I had trouble joining areas together and think I've pressed something I shouldn't have. However, there are so many options I'm not sure what I did.  Here is an image of what I mean   The one on the left has the shadow. As a test I started a new model, which is on the right in the image, and as you can see it doesn't have any shadows.  Also, occluded vertices partially show through the model. Occlusion doesn't work properly.   In orthogonal view small darkened triangles appear along the the edges.    I don't really want to start the model again from scratch so any ideas on how to remove this shadow would be great. Thanks. How can I do the following in Git?  My current branch is branch1 and I have made some local changes. However, I now realize that I actually meant to be applying these changes to branch2. Is there a way to apply/merge these changes so that they become local changes on branch2 without committing them on branch1? Brasero says it won't burn the CD because the file is too big, what's going on? How to ‘guess’ if a noun is countable or uncountable? Problem  The sequence $(a_n)_{n=1}^\infty$ is given by recurrence relation:   $a_1=\sqrt2$, $a_{n+1}=\sqrt{2+a_n}$.   Evaluate the limit $\lim_{n\to\infty} a_n$.  Solution   Show that the sequence $(a_n)_{n=1}^\infty$ is monotonic. The statement $$V(n): a_n &lt; a_{n+1}$$ holds for $n = 1$, that is $\sqrt2 &lt; \sqrt{2+\sqrt2}$. Let us assume the statement holds for $n$ and show that $V(n) \implies V(n+1)$. We have that $$a_n &lt; a_{n+1}.$$ Adding 2 to both sides and taking square roots, we have that $$\sqrt{2+a_n} &lt; \sqrt{2+a_{n+1}},$$ that is $a_{n+1} &lt; a_{n+2}$ by definition. Find bounds for $a_n$. The statement $$W(n): 0 &lt; a_n &lt; 2$$ holds for $n=1$, that is $0 &lt; \sqrt2 &lt; 2$. Let us assume the statement holds for $n$ and show that $W(n) \implies W(n+1)$. We have that $$0 &lt; a_n &lt; 2.$$ Adding two and taking square roots, we have that $$0 &lt; \sqrt2 &lt; \sqrt{2+a_n} &lt; \sqrt4 = 2.$$ The limit $\lim_{n\to\infty} a_n$ exists, because $(a_n)_{n=1}^\infty$ is a bounded monotonic sequence. Let $A = \lim_{n\to\infty} a_n$. Therefore the limit $\lim_{n \to\infty} a_{n+1}$ exists as well and $\lim_{n \to\infty} a_{n+1} = A$. (For $(n_k)_{k=1}^\infty = (2,3,4, \dots)$, we have that $(a_{n_k})_{k=1}^\infty$ is a subsequence of $(a_n)_{n=1}^\infty$, from which the statement follows.) We have that $a_{n+1} = f(a_n)$. That means that $A = \lim_{n\to\infty} a_n = \lim_{n \to\infty} {f(a_n)} = f(\lim_{n \to\infty} a_n) = f(A) = \sqrt{2 + A}$. Solving the equation $A = \sqrt{2 + A}$, we get $A = -1 \lor A = 2$. Putting it all together, we get that $A = 2$, because the terms of the sequence are increasing and $a_1 &gt; 0$.   Is my solution correct? move file by list in file (with leading whitespace) How to find and replace a string by increasing its numerical part? Prove continuous functions $f$ and $g$ are equal Who owns the copyright to S[OFU] content? What with  today, possibly this is a good time to ask: who actually owns the copyright to questions, answers and comments submitted to StackOverflow and relatives?  Over in , we have the OP reaching the conclusion that SO owns the copyright and is licensing it under CC-Attribution-Sharealike, with no apparent confirmation or denial from staff, and in  we have a moderator asserting that Jeff owns the copyright to SO content.  As I note in a comment on the latter, though (which was met with deafening silence), I'm failing to find any evidence that this is the case.  I've looked for any kind of terms of service I may have agreed to indicating that I am signing over ownership of my words when I hit submit, and I can't find one.  Certainly the fact that I'm agreeing to CC-Attribution-Sharealike licensing is clear enough, but it seems to me as if I am retaining copyright while agreeing to those licensing terms, and S[OFU] is using what I have written under that license.  What's the deal?  Did I forget about something that I agreed to in the signup process (and if so, why can't I find it afterward)?  Do the owners and administrators of S[OFU] believe that they own copyright to the UGC?  Just what is going on here?  Edit as to why this matters (from answer comment thread): If I retain copyright, I can also choose to license the original content to other parties under other terms (such as using a zero-requirements license, using an attribution-required license without sharealike, etc). If SO has the copyright, I can't. Why is $\frac{\operatorname dy'}{\operatorname dy}$ zero, since $y'$ depends on $y$? I know that $\frac{dy'(x)}{dy}=0$ (where $y'=\frac{dy(x)}{dx}$). The reason explained is that $y'$  does not depend explicitly on $y$. But intuitively, $y'$ depends on $y$, since if you vary $y$ you will modify $y'$. Why is my reasoning wrong (my reasoning sounds like it's related to functional calculus, instead of standard calculus)?  I tried to write  $\frac{dy'(x)}{dy}=\frac{d}{dy}\frac{dy}{dx}=\frac{d}{dx}\frac{dy}{dy}=\frac{d}{dx}1=0$, but this proof doesn't convince me.  I think that other way to see this is saying that if a function is of the form $f(y)$, it will not dependend on the variable $y'$.  But the same way you write $f(y)=y^2$, you could write $f(y)=\frac{d}{dx}y$, which clearly depends on $y'$. So I don't know if there are some types of operations which are restricted (for example, taking limits):  Note: The problem raises in the context of Classical Mechanics, where: $\frac{\partial L(\dot{x},t)}{\partial x}=0$. Automatically capitalise the first word in each sentence How to write startup script for Systemd? I have 2 graphics cards on my laptop. One is IGP and another discrete.   I've written a shell script to to turn off the discrete graphics card.  How can I convert it to systemd script to run it at start-up? Does the order of declaration matter in Java/C#? Can I get a postdoc in China more than 3 years after having received my PhD? found a 1994 uncashed profit sharing retirement plan check I have a basic grammar question about the past tense. If I met a guy yesterday, which tense should I use about his name today?  For example,     "Yesterday I met a guy, his name is/was John." Union of uncountable cardinals My colleague and I were discussing about certain types of customers in the IT industry. You have to work extremely hard to convince them so that they think about opening their wallets .  However, they should not be mistaken to be stingy (carries a negative connotation). Cost-conscious is a closely related term but is a bit wordy. Another word that I considered is shrewd but I don't know if it fits my context well.  Usage Sentence:     Nowadays, IT customers are becoming increasingly ________. They demand more for less and probably think a zillion times before reaching for their pockets. If they are not convinced 100%, they simply won't open their wallets.    Is there is a noun or an adjective to describe such people? I am also open to using idioms, if there is one that conveys the intentions well.  N.B:  I am looking for words with neutral to positive connotations. rsync two existing directories copying everything I have two file servers in two locations. Currently both have the same data, which generally is unmodified (used for read only access).When the second server was set up (the one I'm sshing to) the data was copied over LAN and has since been moved geographically.  I'm trying to use rsync for the first time on the required directories. An example command;  sudo rsync -avz --ignore-existing -P --dry-run /media/Storage/OSs/ user@mydomain:/mnt/Storage/OSs/   I've tried using -c -t -u (Additionally went on the remote server and updated the timestamps to today) also but every time I execute a dry run it wants to copy everything!  Additionally the user is the same for both machines with the same UID.  *Edit  After playing around a bit more, I've found that rsync does not like the whitespace in the subdirectory names; For instance if I use ' to escape local shell &amp; \ to escape remote shell     sudo rsync -avz --ignore-existing -P '/media/Storage/OSs/Windows/Windows server 2011/' 'user@mydomain:/mnt/Storage/OSs/Windows/Windows\ server\ 2011/'   Then all is well, my theory is then that rsync does not like the subdirectories with whitespaces. I have thousands of subdirectories; the only solution I can think of is to write a small python/shell script to run each sub directory separately but is undesirable. Show that $(2,0,4) , (4,1,-1) , (6,7,7)$ form a right triangle What I tried:  Let $A(2,0,4)$, $B(4,1,-1)$, $C(6,7,7)$ then  $$\vec{AB}=(2,1,-5), \vec{AC}=(4,7,3), \vec{BC}=(2,6,8)$$  Then I calculated the angle between vectors:  $$\begin{aligned} \alpha_1 &amp;= \cos^{-1}\left(\frac{(2,1,-5)(4,7,3)}{\sqrt{2^2+1^2+(-5)^2}\sqrt{4^2+7^2+3^2}}\right) \\ &amp;= \cos^{-1}(0)=90° \\ \alpha_2 &amp;= \cos^{-1}\left(\frac{(4,7,3)(2,6,8)}{\sqrt{4^2+7^2+3^2}\sqrt{2^2+6^2+8^2}}\right) \\ &amp;= \cos^{-1}\left(\frac{74}{\sqrt{74}\sqrt{104}}\right)=32.49\\ \alpha_3 &amp;= \cos^{-1}\left(\frac{(2,6,8)(2,1,-5)}{\sqrt{2^2+6^2+8^2}\sqrt{2^2+1^2+(-5)^2}}\right) \\ &amp;= \cos^{-1}\left(\frac{-30}{\sqrt{104}\sqrt{30}}\right)=122.5° \end {aligned}$$  As you can see, these angles don't even form a triangle, what am I doing wrong, any thoughts?