In Norwegian schools,  is widely used for plotting graphcs, calculus, algebra, etc. However, by the looks of it, it is not very commonly used, so the documentation and resources is very limited (especially on the Computer Algebra System). Is there any good alternatives to it? What is most used in other countries/professionally? This is only basic functions, like finding derivatives/extrapolating and solving polynomial equations, no 3D.
Does it exist a free interactive geometry software, like GeoGebra, which works for 3D geometry? I would be able to draw spheres, great circles, and so on.
Is there an exact command for restarting GNOME Shell in Ubuntu 20.04 corresponding to Alt + F2 + 'r' + Enter? Is there a way to restart GNOME Shell other than by using Alt + F2, R + Enter? With respect to the question, I have gone through , but I didn't get what I was looking for. I am looking for a command which exactly does what Alt + F2, r + Enter do. Please note that I am not willing to do the gnome-shell -- replace command... I did check both the things Alt + F2,r Enter and gnome-shell --replace... There is a lot of difference, I found... How do I know if food left at room temperature is still safe to eat? If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more? Watched screen recording but it's not saved to the desktop I recently recorded a session with my dad. I stopped the recording after the session ended (with the setting set to save to Desktop), clicked the icon that appeared on the lower right corner to open the file, and played back a few minutes to make sure it worked. I then clicked Share to send it via AirDrop to my computer, which did not work; the status remained &quot;cancelled&quot; despite my efforts. I assumed I'd be able to access it through my phone by sending it through a third app, so I pressed cancel on the AirDrop pop-up window. The entire screen recording closed and (apparently) vanished forever after the action. I'm extremely frustrated because I can't seem to locate this video. I  as unclear what you're asking after receiving flags on it in the moderator queue.   Once I did that, the text for the question title in the moderator queue changed from:     How to use handler to display images from database without passing ID in querystring?    to     How to use handler to display images from database without passing ID in querystring? [undefined more votes needed]    The text on the main page has stayed consistent with the new 'on hold' verbiage, however.  Here's a screenshot: Windows 7 Automatically Connecting To Unsecured Wireless Networks On Startup Most of the questions on this topic related to folks connecting to somebody else's wireless network when their own was available and could remedy the situation by going to their connections and unchecking the "connect automatically" box.  See this: "  " as an example.  In my situation, I've noticed that Win 7 will automatically connect to any unsecured wifi network - even if I have never connected to it in the past.  If I am traveling and boot Win 7, it will start and connect to what appears to be the best signaled unsecured network without prompting me for confirmation (note: in the above link, "Naveen" seems to have same problem).  Obviously, that is a security concern to me.  Further, when I open "Network and Sharing" and "Manage wireless networks"  the network is not displayed (probably because I labelled it a public network).  Again, these are new, never connected with before, wireless networks.  I always promptly disconnect from them but don't want to have to be on constant guard for an auto connection to a malicious network.  This began about a month ago, as I recall, Win 7 did not behave like this in the past, I didn't monkey with wifi settings, and don't use a 3rd party connection manager.  I did have to download some internet security certificates for army website access but I don't think that should mess with network settings.  Any ideas how I can tell Win7 cease automatically connecting to networks or, at least, to prompt me for a confirmation before connecting? Prove that: $\sqrt{2\sqrt{3\sqrt{4\cdots\sqrt{n}}}}<3,\,\forall n\in\mathbb N.$ I was writing a toString() for a class in Java the other day by manually writing out each element of the class to a String and it occurred to me that using reflection it might be possible to create a generic toString() method that could work on ALL classes. I.E. it would figure out the field names and values and send them out to a String.  Getting the field names is fairly simple, here is what a co-worker came up with:  public static List initFieldArray(String className) throws ClassNotFoundException {      Class c = Class.forName(className);     Field field[] = c.getFields();     List&lt;String&gt; classFields = new ArrayList(field.length);      for (int i = 0; i &lt; field.length; i++) {         String cf = field[i].toString();         classFields.add(cf.substring(cf.lastIndexOf(".") + 1));     }      return classFields; }   Using a factory I could reduce the performance overhead by storing the fields once, the first time the toString() is called. However finding the values could be a lot more expensive.  Due to the performance of reflection this may be more hypothetical then practical. But I am interested in the idea of reflection and how I can use it to improve my everyday programming. I have to maintain a large number of classic ASP pages, many of which have tabular data with no sort capabilities at all. Whatever order the original developer used in the database query is what you're stuck with.  I want to to tack on some basic sorting to a bunch of these pages, and I'm doing it all client side with javascript. I already have the basic script done to sort a given table on a given column in a given direction, and it works well as long as the table is limited by certain conventions we follow here.    What I want to do for the UI is just indicate sort direction with the caret character ( ^ ) and ... what?  Is there a special character that is the direct opposite of a caret?  The letter v won't quite cut it.  Alternatively, is there another character pairing I can use? Lots of questions in the reopen queue I'm trying to find a post I made on my timeline (aka wall) several months (or even years) ago, but can't find a way to search for it. I , but that's very heavy.   Currently, I open the activity log (e.g., https://www.facebook.com/username/allactivity) and start scrolling down to get some info on the page. Then I use my browser to search for the text. But this is slow and, depending on how far back I want to go, tedious. Clicking on the earliest month/year in the filter only loads those periods specifically.    Anyone know of a better way that will find the search words anywhere on your activity log quickly?    Edit: There's a  (not really a bug, but lack of a feature) related to this on Facebook's developers forum. Can only search social network messages in the Dash after 13.10 upgrade How to restore original size and unboot my bootable USB pendrive Motivation for Ramanujan's mysterious $\pi$ formula The following formula for $\pi$ was discovered by Ramanujan: $$\frac1{\pi} = \frac{2\sqrt{2}}{9801} \sum_{k=0}^\infty \frac{(4k)!(1103+26390k)}{(k!)^4 396^{4k}}\!$$   Does anyone know how it works, or what the motivation for it is? I have a Mac that runs Snow Leopard and I intend to upgrade it to Mountain Lion and sell it on ebay. However, I only have one hard-drive, and I'm sure I can't use something in my OS to delete my OS and all user data.  Is there something for this that's built into the firmware that I can do on boot, or otherwise?   I have source code on my Mac for multiple corporations' proprietary software and I can't risk somebody gaining access through the use of any sort of disk recovery tool. I plan to use a 7 pass erase rather than simply deleting the directory. Sneak Damage multiplier: Does it apply to magical damage too? Example:   Dagger 1 = 18 Damage, 25 Shock  Dagger 2 = 33 Damage, no magic  Using the above, when I sneak attack and have the 15x multiple then is the damage caused by Dagger 1 is (18+25)*15 or (18*15)+25 ?  Same question with bows and arrows, does the multiplier apply to potion damage or/and the magical(enchanted)?  In other words, do the multipliers apply to the base damage only or to the final damage being caused by the weapon (base+magical+skill+potion+perks etc)?  I am confused. :-? Characterization convex function. Prevent browser caching of AJAX call result It looks like if I load dynamic content using $.get(), the result is cached in browser.  Adding some random string in QueryString seems to solve this issue (I use new Date().toString()), but this feels like a hack.   Is there any other way to achieve this? Or, if unique string is the only way to achieve this, any suggestions other than new Date()? Get the image URL I want to render an image as a background image via an inline style in twig. I created a field called bg_image and attached it to the standard plain page.  After fiddling around for hours I was able to get the Image URL in node.html.twig  {{ file_url(node.field_bg_image.0.entity.uri.value) }}   but I could not get it to work inside field--field-bg_image.html.twig  Can I get the node from there anyhow, so I can then get the image?  How can I get the image URL to use as inline style? I thought maybe I can pass a variable from field--field-bg_image.html.twig to image.html.twig and then just render  {{ uri }}   instead of  &lt;img{{ attributes.addClass(classes) }} /&gt;   but I could not get it to pass the variable there unless I use includes  {% include 'image.html.twig' with {'image': image, 'isFromField': isFromField} %}   (isFromField is true, when it comes from the field--field-bg_image.html.twig) But that didn't work either. The Image was never rendered that way.  Would be very glad if you can help - my php knowledge is very basic. Thanks Find the limit $\lim_{n\to\infty} \frac{x_1 y_n + x_2 y_{n-1} + \cdots + x_n y_1}{n}$ When $\lim_{n\to\infty} x_n = a$, and $\lim_{n\to\infty} y_n = b$, find the limit, $$\lim_{n\to\infty} \frac{x_1 y_n + x_2 y_{n-1} + \cdots + x_n y_1}{n}.$$ Thank you for your help in advance. What happens when yellow light is passed through a prism? What happens when secondary colors like yellow,green and magenta are passed through a prism? Will it split into its component colors(for example yellow split into green and red)?If yes why we are observing secondary colors in the visible spectrum obtained when white light(composite light) is passed through a prism?