I use OSX most of the day, but recently built a new desktop PC and started using Windows 10 as well. On my Mac, when I hold the Alt key, the keyboard uses the English keyboard layout, but only as long as I hold it down. This way I can quickly type characters that are not available that easily on my native (Czech) keyboard, and return to native without additional key press.  On Windows, there are alternative shortcuts to type the different characters (for example Alt+V to type @). Is there a way to make my Windows work like macOS?  To clarify, I am not asking how to switch layout with shortcut press. I´d like to be able to write with different layout while I hold down certain key (like Alt). After releasing it, it goes automaticaly back to my language.
OS X has this really nice feature when you have 3+ keyboard input sources (languages) and press Cmd + Space you switch between only two of them.  If you want to switch to another (third) language you just hold Cmd and press Space to choose from the list of input sources available.  How can I have similar functionality on Windows 10? I have 3 input sources and looping through them to get to the one I need is really annoying.
Suppose we are in $\mathbb R^n$. What can we say about the sign of $\Delta u(\vec x)$ if u($\vec x$) has a local max/min at $\vec x$? I've tried looking at the reverse of the second partial derivative test and it seems to suggest that $\Delta u(\vec x) \leq 0$ if $\vec x$ is a min and $\Delta u(\vec x) \geq 0$ if $\vec x$ is a max. However, I'm not convinced of this result. Can somebody point me towards a statement (theorem, etc.) involving the above. I appreciate the help. How to Straighten Curved UVs into Straight Belt Showing the actual 3D model of a curving ramp.  Shows the UVs of that model that blender did automatically. Shows the UV image that I need.   I am going put a road texture on it., but round faces are not helping me at all. All I need is straight belt kind of UV. setting up apache2 webserver -- differences between behaviour within my intranet and outside When I press the power button on my Epson WorkForce WF-3520 printer, it starts up normally, but shuts down within 30 seconds. Ten seconds later, it starts itself and the stop/start cycle is repeated again and again. This has only started happening today (6th December 2016). Quick way to subtract white outline from knotwork pattern in Illustrator? I am working with a pretty complex traced AI that I received, and I want to basically make it so that all the visually black stuff is shapes, and all the white outlines (invisible here) are removed. Most of the spaces when a line crosses over another is created by a white outline.   I know about expanding appearance and the pathfinder tool, but because there are so many lines that are crisscrossing, I haven't had an easy way of minusing the fronts away. I could expand appearance and sort every object carefully, but I feel like there may be a quicker way of doing this.  If I put it in Photoshop as a smart object in 'screen' mode, it looks right.. I could put that back in Illy and trace it, but I don't want to complicate the paths. Functional equation $f(r \cos \varphi)+f(r \sin \varphi)=f(r)$ Find all such monotonous function $f:[0,+\infty)\to \mathbb R$, such that for any real $r\ge0$ and $\varphi \in \left[\frac{\pi}6, \frac{\pi}4\right]$, $$f(r \cos \varphi)+f(r \sin \varphi)=f(r)\text.$$  My work so far:  If $\varphi \in \left[\frac{\pi}6, \frac{\pi}4\right]$ then $$\frac{\sqrt2}2\le\cos \varphi\le\frac{\sqrt3}2$$ $$\frac12\le\sin \varphi\le\frac{\sqrt2}2$$  If $r=0$ then $f(0)=0$  If $\varphi= \frac{\pi}{4}$ then $$f(r)=4f\left(\frac r2\right)$$  $f(x)=cx^2$ for $x\ge0$ and $c\in\mathbb R$ Why does my procedure run slowly until I update statistics? What does the author mean by 'back to back' and 'hidden city' ticketing hacks? At this link about   what does the author mean by this?   Back to back and hidden city ticketing. Sometimes airlines will charge far more for tickets to that do not include a Saturday night stay, on the assumption that those passengers are business travelers who aren’t flexible and can afford to pay more. Yet those who commute between cities eventually realize that they can purchase one round-trip ticket that covers their first outbound and last return, followed by round-trip tickets to return home on the weekends. Why there is much interest in the study of $\operatorname{Gal}\left(\overline{\mathbb Q}/\mathbb Q\right)$? How do I get a block with data to place myself? How do I install software using the Ubuntu Software Center? The title says it all. I'd like to know how I can install software - an example is the Chromium web browser. Why won't SparseArray let me store values with the head List? To Find Large Powers in C++ Please consider gathering Meta feedback before the "ship" stage Bravo for allowing comment editing, but what's the explanation for enforcing a five-minute window?  I think this might be over-engineering. If I have a spelling mistake or an inaccuracy I'd like to fix, I don't think the fact that five minutes has elapsed should prevent me from fixing it.  Further, if you are worried people will edit their comments in a way that makes the comment thread nonsensical, they can already do this by deleting their comment. So, limiting the ability to edit isn't really helping much in that regard.  Update  If people don't like this idea, I'm definitely open to hearing your reasons. For now, it seems like an unnecessary limitation of a quite awesome feature.  Update 2  Regarding John's scenario...     Me: Obama is cool!   You: You are right, man!      My edit: Obama is an idiot!   You: You are right, man!   ...this problem can still occur with deletions...     user1: Obama is cool!   user2: No, McCain is cool!   you: You are right, man!        user1: Obama is cool!   ---- deleted -----   you: You are right, man!     So, yes, editing could be abused as you suggest, but discontinuities can occur already because of deletions (and as someone else mentioned, because upvoted comments get prioritized upward).  As for Jeff's argument about rate limiting, I agree that is important, but I don't understand why you can't just use a CAPTCHA to prevent too many edits in a short period of time. How do the definitions of "irreducible" and "prime" elements differ? Sum of nil right ideals If a function is a combination of other functions whose derivatives are known via composition, addition, etc., the derivative can be calculated using the chain rule and the like. But even the product of integrals can't be expressed in general in terms of the integral of the products, and forget about composition! Why is this? Deriving the speed of the propagation of a change in the Electromagnetic Field from Maxwell's Equations I've been told that, from Maxwell's equations, one can find that the propagation of change in the Electromagnetic Field travels at a speed $\frac{1}{\sqrt{\mu_0 \epsilon_0}}$ (the values of which can be empirically found, and, when plugged into the expression, yield the empirically found speed of light)  I'm really not sure how I would go about finding $v = \frac{1}{\sqrt{\mu_0 \epsilon_0}}$ simply from Maxwell's equations in the following form, in SI units --  $$\nabla \cdot \mathbf{E} = \frac {\rho} {\epsilon_0}$$  $$\nabla \cdot \mathbf{B} = 0$$  $$\nabla \times \mathbf{E} = -\frac{\partial \mathbf{B}} {\partial t}$$  $$\nabla \times \mathbf{B} = \mu_0 \left( \mathbf{J} + \epsilon_0 \frac{\partial \mathbf{E}} {\partial t} \right)$$  Is what I believe true? (that the speed of propagation is derivable from Maxwell's Equations)  If not, what else is needed?  If so, can you provide a clear and cogent derivation? How to extend USB beyond the recommended maximum cable length of 5m? I'm planning to use USB port for an application(from a device to a PC) but the distance between the device and the PC will be around 15m. The recommended maximum USB cable length is 5m.  How can I buffer the data without loosing any information, safely? Would a USB hub work?