Marking the minimum point of a quadratic
adding a point in a manipulate command
Is posting someone's comment as an answer okay? I came across  and at the time there were no suggested answers. After reading Mark Hubbart's comment (at the time with four upvotes), which was the correct answer, and seeing that it had been over 30 minutes since his comment, I figured I would provide that answer in my own words, which I did. My answer is longer, and I think more rounded and more useful, but the core of the answer came from the comment. I have no idea if I'd have thought up the answer on my own--a definite maybe to that.  Now had I tried to be "honorable" or something, such as instead of answering, suggesting to the commenter that he make his comment an answer, I would only have accomplished giving away easy rep to some other user not as into gratuitous self-denial.  The commenter had merely to enter his comment into an answer box instead of a comment box! It was his choice! Whether he was too lazy or didn't think his answer worthwhile or some other reason is not my responsibility. Must I bend over backward to help him earn points that he so carelessly left lying around for another person to take? It just took a tiny bit of non-laziness on my part to get my text typed into the box that would reward me instead of the box that wouldn't.  If my perspective is incorrect and the community would rather see such answers-as-comments rewarded and supported, I will gladly accept that. In the meantime, I just want to shake off the tiny bit of guilt my overly-nice and overly-concerned-with-propriety self is feeling. :) Interpretation of R's lm() output A couple years ago, it was easy to root any device: Install KingRoot, KingoRoot, or a similar app, hit the large ROOT button, and let it do the rest. After 5 minutes or so, a green "Root Succeeded!" prompt will pop up, and we can choose to keep the root app, or uninstall it and install a clean root manager app like SuperSU/Superuser.  How do they work? Why aren't they working anymore? And if they work, should I use them or not? 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. Why won't SparseArray let me store values with the head List? List all commands that a shell knows What can I type at my shell (which happens to be bash) that will list all the commands that are recognized?  Also, does this differ by shell? Or do all shells just have a "directory" of commands they recognize?  Secondly, different question, but how can I override any of those? In other words how can I write my own view command to replace the one existing on my Ubuntu system, which appears to just load vim. Force alt + tab to switch only on current workspace in GNOME shell Natural Sort Order in C# Anyone have a good resource or provide a sample of a natural order sort in C# for an FileInfo array?  I am implementing the IComparer interface in my sorts. Simple past or present perfect? Which is preferable, simple past or present perfect, in situations like this one: I had a conversation with my friend and we planned to do something; shortly afterwards I call him back to announce the accomplishments. My biggest doubt about simple past is that perfect aspect is used to indicate past action (accomplishment) with current relevance, at the same time I'm not sure if I'm allowed to use present perfect, because there's a gap between accomplishing and the current moment, which is a characteristic of simple past. Allow users to hide connections between accounts This feature request is inspired by the question on Programmers.SE on .   Stack Overflow is a site aimed at professional programmers, and it is used by some employers and some employees to examine or showcase the candidates abilities. I don't see any problem with that, but there is one aspect I'm a bit concerned about. Certain SE sites are far more private than the professional sites like SO. Anyone that participates in Christianity, Judaism, Islam or Biblical Hermeneutics is likely giving out a significant amount of information about their personal belief or world view to anyone who can connect the user name to the actual person. Another example would be controversial topics on Skeptics or Politics; not everyone would like to give their employer access to that kind of information.  The fundamental problem is that the SE platform does not allow for any separation inside one account. Of course one could create separate accounts for private and professional topics, but that requires a significant amount of clairvoyance and a rather annoying user experience juggling separate browsers to log into different accounts at once. An additional problem is that SE has automatic user merge features that can be triggered by logging into two accounts in the same session. I'm not sure how they work exactly, but I suspect that having your two accounts accidentally merged is a real danger if you are not careful.  There should be a mechanism to hide the connection between SE accounts, without having to use separate OpenIDs. For example, if I would like to use my SO account in job applications, I should be able to separate it from all my other accounts. The separation would only be for the publicly accessible part, moderators could still be allowed to see the connection between accounts. And behind the scenes it would just work as it is now, just without any links between the accounts.   The aspects that would need to be changed that I can think of are   the accounts tab in the user profile, that shouldn't show any connections for separated profiles copying the user profile to other sites should not work for separated profiles the network profile should not show the connections between separated profiles Area 51 should also not show the profile connections   This separation would not have to be bulletproof, but it should prevent users googling a specific person to make connections the user does not want to make public. Why is it possible to answer a question twice? You normally answer a question and you have the opportunity to answer again. The second time, a message is shown suggesting the use of the edit tool, but I think it's kind of wrong. I mean, if you answer something and then you want to say anything else you know that you must use edit.  Why not disable the answer button if you already have an answer? I need a two word phrase to refer to a community of people (academia + non-academia) who come together to share/exchange their knowledge/ideas openly on topics of their interests/ specializations.  I would appreciate the use of small and easier/common words for the phrase. Single words are also acceptable. Feel free to throw out your creative ideas and newly invented phrases. I'm unable to upgrade Xcode 11GM to 11.1 for some time on my Mid 2014 MacBook Pro running macOS Catalina. I've installed Xcode from Mac AppStore ages ago (IIRC circa 2014), and upgraded step by step since then. Currently, I'm experiencing the following loop:   AppStore reports that I have an update. I open AppStore, open updates, click "Update" on Xcode. Mac Downloads ~2.5GB first. Installs that patch. Continues to get the full package (~7.6GB). It starts to install. After some churning and install, it reports "Cannot download Xcode now, please try again later."   I have more than enough space on the disk, and nothing is modified in Xcode or in the OS (no homebrew or something similar).  Did anyone experience something similar? Are there solutions to this? Printing an array to a file with each element of the array in a new line in bash How can I control a servo motor with the PWM output of a microcontroller? I wanted to control the direction of servo motor with a switch. I am using an Atmega32.  Outputs are PIND4 and PIND5 and the input is PINA3, but the two servo motors turn only in 1 direction.  #ifndef F_CPU  #define F_CPU 1000000UL   #endif  #include &lt;avr/io.h&gt; #include &lt;util/delay.h&gt; #include &lt;avr/interrupt.h&gt;   int main(void) { DDRD= 0xFF ; DDRA=0x00; PORTA =0x00; // FAST PWM TCCR1A |= 1&lt;&lt;COM1A0 | 1&lt;&lt;COM1A1 | 1&lt;&lt;WGM11 |1&lt;&lt;COM1B0|1&lt;&lt;COM1B1 ; TCCR1B= 1&lt;&lt;WGM12|1&lt;&lt;WGM13 ; ICR1 = 19999 ;  TCCR1B |=1&lt;&lt;CS10 ; while (1) {    if(PORTA==0x08) //if pina3 is 1    {     OCR1A = ICR1 -2000 ;   //turn servo 1     _delay_ms(1000);          OCR1B=ICR1-2000;    //turn servo 2     _delay_ms(1000);     }     if(PORTA==0x00)// if pina3 is 0     {       OCR1A = ICR1 -900 ; //turn servo 1 in the other direction       _delay_ms(1000);               OCR1B=ICR1-900;     //turn servo 2 in the other direction       _delay_ms(1000);      } }       return 0 ;  } Cannot mount USB stick - errors out with "$MFTMirr does not match $MFT" What exactly is 'Dark Matter'? When deriving the quadratic equation as shown in the  () the main proof contains the step: $$ \left(x+{\frac {b}{2a}}\right)^{2}={\frac {b^{2}-4ac}{4a^{2}}} $$ the square root is taken from both sides, so why is  $$\sqrt{4a^2} = 2a$$  in the denominator and not $$ \sqrt{4a^2} = 2\left |a  \right | $$ Could somebody explain this to me? Thank you very much Tools for tracking NPC/PC relationships and attitudes I have always had difficulty keeping track of NPCs, their attitudes and their relationships with each other and the PCs. I find relationship webs/diagrams are helpful, but find them difficult to keep up to date and accurate from session to session.  Are there any tools that would help with this task? I am aware that some general mapping software exists, but am more interested in tools specifically designed for RPGs. Also, I would prefer a graphical interface if software is suggested, and to not have to learn a text based language to define the diagram. However, if it turns out that the only tools available are more generalised, and/or complex, I would still like to hear about them as answers. How to change default window background color in Windows 10?