Derivation of equation of hyperbola - Where does the b²=c²-a² come from?
A geometric reason why the square of the focal length of a hyperbola is equal to the sum of the squares of the axes?
How to deal with SQL column names that look like SQL keywords? One of my columns is called from. I can't change the name because I didn't make it. Am I allowed to do something like SELECT from FROM TableName or is there a special syntax to avoid the SQL Server being confused? Make file in linux readonly GLR Test for 2 samples from exponential distributions Custom DataTable using Vanilla Datables in LWC I'm trying to build a custom datable because I want the functionality to sort, search and paginate and also add action buttons in each row. Initially, my VF page was using  but we have now decided to rebuild that page in LWC.  I found a similar  but it hasn't really worked for me.  I then found  (Javascript) and  (ES2018) I have tried to implement Vanilla Datatables but I keep running into issues such as:      TypeError: Cannot read property 'length' of undefined   The above error is thrown because the library is unable to find the body of the table.   My point is that I feel this library won't work because it's using document, window and so on.   I was wondering if there is a way I could convert this library to something that is more suited to LWC basically have it "export" the modules. Since I'm not a JS expert I'm unable to put the pieces together.   Just for some context, I'll post my code here:  &lt;template&gt;     &lt;table class="sobject-table slds-table slds-table_cell-buffer slds-table_bordered"&gt;         &lt;thead&gt;             &lt;tr class="slds-line-height_reset"&gt;                 &lt;template for:each={fieldSetData} for:item="field"&gt;                     &lt;th key={field.apiName} title={field.fieldLabel} class="" data-scope="col"&gt;                         &lt;div class="slds-truncate" title={field.fieldLabel}&gt;{field.fieldLabel}&lt;/div&gt;                     &lt;/th&gt;                 &lt;/template&gt;             &lt;/tr&gt;         &lt;/thead&gt;         &lt;tbody&gt;             &lt;template for:each={records} for:item="row"&gt;                 &lt;tr key={row} class="slds-hint-parent"&gt;                     &lt;template for:each={row} for:item="data"&gt;                         &lt;td key={data.id} data-label="Name" data-scope="row"&gt;{data.value}&lt;/td&gt;                     &lt;/template&gt;                 &lt;/tr&gt;             &lt;/template&gt;         &lt;/tbody&gt;     &lt;/table&gt; &lt;/template&gt;   import {LightningElement, api, wire} from 'lwc'; import {processRecords} from 'c/recordGenerator'; import getFieldSetData from '@salesforce/apex/FieldSetData.getFieldSetData'; import getSobjectRecords from '@salesforce/apex/DeomoCTRL.getRecords'; import VanillaDatatable from '@salesforce/resourceUrl/VanillaDatatable'; import {loadScript, loadStyle} from 'lightning/platformResourceLoader';  export default class ManageSelectedIndicators extends LightningElement {     @api recordId;     records;     fieldSetData;     @wire(         getFieldSetData,         {objectName: 'SOBJECTName', fieldSet: 'FIELSETName'}     ) wiredFieldSetData({error, data}) {         console.log('wired called in Child')         if (data) {             this.fieldSetData = data;             this.getData();         }     }       constructor() {         super();         console.log('Constructor called in Child');     }      connectedCallback() {         console.log('Connected callback');     }      renderedCallback() {         console.log('Rendered callback');         Promise.all([              loadScript(this, VanillaDatatable + '/VanillaDataTables/src/vanilla-dataTables.js')          ]).then(() =&gt; {              const table = new DataTable(                  document.getElementsByClassName('.sobject-table'),                  //Also tried this.template.querySelector('.sobject-table'),                  {searchable: true, sortable : true}              );          })          .catch(error =&gt; {             console.log(error);          });     }      getData() {         getSobjectRecords ({             sobjectId: this.recordId         })         .then(response =&gt; {             this.records= processRecords(response, this.fieldSetData);         })         .catch((error) =&gt; {             console.log(error);         });     }  }   Edit: I have also tried lwc:dom="manual" that didn't seem to work either.  Is there any other way I could achieve these functionalities? Or do I have to write custom code to achieve this? A problem about wave equation Parenthesis vs brackets for matrices When I first learned linear algebra, both the professor and the book used brackets like [ and ] to enclose matrices. However, in my current differential equations textbook, matrices are enclosed by parenthesis, and I suddenly realize everybody else are using them too.  So are brackets/parenthesis for enclosing matrices always totally interchangeable? How do I print a #defined constant in GDB? Pick random row from a file How to represent it with UNIQUE indexes and foreign keys? "Group" is a group of pupils. "Topic" is a topic of lessons.  To every group corresponds exactly one topic. (So there may be multiple groups per topic.)  To a pupil corresponds multiple groups, but maximum one group per topic.  How to implement this in terms of UNIQUE indexes and foreign keys in MySQL? How to create a meta-package that automatically installs other packages? I'd like to be able to create a package that doesnt contain any code or programs itself, but instead installs other packages that exist in the repositories onto a computer, sort of how the ubuntu-restricted-extras package does? Find duplicate records in MySQL I really love Eclipse (PDT)... But i'm developing sites using HTML5 and CSS3 and it mark the HTML5 tags like &lt;nav&gt;, &lt;section&gt; and &lt;article&gt;  as invalid tags (inexistent).  How can I add those new tags to it?  And what about CSS3 rules?  I read something about remove the "invalid tag" check... and that's not what I want. :( What is the volatile keyword useful for? Proving the snake lemma without a diagram chase Do airlines have to check the visa status before selling a ticket? Does removing an iPhone from my icloud account also erase the data? I lost my iPhone 6S recently. I think it fell off my car and was crushed because it has been offline (according to Find My iPhone) ever since. I want to erase the phone and remove it from my iCloud account since the phone is gone.  However, I can't erase the phone until it comes back online. I do have the option to remove the device from my iCloud account. If I remove the phone from my iCloud account, does that also erase the data? The phone has a password on it, will it continue to be locked in case someone finds it after I have removed it from my iCloud account? What rolls should players get to see? I'm a new DM and over the last few weeks I've been slowly learning the game and how it runs. My party consists of 5 PCs.   One thing I have been wondering after our last two sessions is: What rolls should all the players see and which rolls shouldn't they see?  Is there a comprehensive list of what rolls are public and which go behind the DM screen, or is it more down to house rules or personal preference? Top of answer covered by sticky top bar after clicking direct link With the introduction of the network-wide sticky top bar , I noticed a bug that's happening on every site (except for Stack Overflow). When you click on an answer link (of the form https://site.stackexchange.com/a/####), the very top of the answer and the upvote button are covered by the top bar:    Stack Overflow shows the correct behavior: Guarding against cryptanalytic breakthroughs: combining multiple hash functions HP laptop F1-12 keys inverted with Fn I recently bought an HP laptop. I'm pleased with it, save for one thing.  All the F1-12 keys are inverted. I mean the following:  All the F-keys have a symbol on it. Normally you would press Fn + your to use it. On this laptop, it's reversed. The symbol is what you get when you press the button normally and you have to press Fn + F-key to get the usual action.  So, if I want to refresh a webpage, instead of just F5, I have to do Fn + F5  I want to change this to regular behavior. Anybody know how I can do this?  Running Win7 Home premium, 64-bit.