Name this simple norm equality! (Real Analysis)Common Ground between Real Analysis and Measure TheoryReal...

Why does the frost depth increase when the surface temperature warms up?

What should be the ideal length of sentences in a blog post for ease of reading?

Is divisi notation needed for brass or woodwind in an orchestra?

Derivative of an interpolated function

How to preserve electronics (computers, ipads, phones) for hundreds of years?

How can I, as DM, avoid the Conga Line of Death occurring when implementing some form of flanking rule?

How do you justify more code being written by following clean code practices?

Sort with assumptions

Connection Between Knot Theory and Number Theory

Should a narrator ever describe things based on a character's view instead of facts?

Weird lines in Microsoft Word

Why is indicated airspeed rather than ground speed used during the takeoff roll?

What is the meaning of "You've never met a graph you didn't like?"

Output visual diagram of picture

How do I lift the insulation blower into the attic?

Reasons for having MCU pin-states default to pull-up/down out of reset

Mortal danger in mid-grade literature

Are hand made posters acceptable in Academia?

What is the tangent at a sharp point on a curve?

If the Dominion rule using their Jem'Hadar troops, why is their life expectancy so low?

In the event of Brexit being postponed beyond the EU elections, will UK voters in EU countries be eligible to participate?

Name this simple norm equality! (Real Analysis)

Does capillary rise violate hydrostatic paradox?

Has the laser at Magurele, Romania reached the tenth of the Sun power?



Name this simple norm equality! (Real Analysis)


Common Ground between Real Analysis and Measure TheoryReal analysis - proof approach helpReal analysis: simple second order ODEDoes this inequality involving the sum of components of a vector and its norm have a name?Why is this Inequality True for all Positive Real Numbers?What is real analysis?Is there a name for this set?Clarification on definition of a norm in a real analysis problemProb. 12, Sec. 5.2, in Bartle & Sherbert's INTRO TO REAL ANALYSIS: Continuity of additive functionsReal Analysis: Not sure if textbook proof is incomplete.













1












$begingroup$


I'm a bit new to real analysis. Today, I came across this particular equality, whcih seems obvious to me.
$$ lVert x + z rVert^2 + lVert x - z rVert^2 = 2 lVert x rVert^2 + 2lVert z rVert^2 $$
Is there a specific name for this?










share|cite|improve this question









$endgroup$

















    1












    $begingroup$


    I'm a bit new to real analysis. Today, I came across this particular equality, whcih seems obvious to me.
    $$ lVert x + z rVert^2 + lVert x - z rVert^2 = 2 lVert x rVert^2 + 2lVert z rVert^2 $$
    Is there a specific name for this?










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      I'm a bit new to real analysis. Today, I came across this particular equality, whcih seems obvious to me.
      $$ lVert x + z rVert^2 + lVert x - z rVert^2 = 2 lVert x rVert^2 + 2lVert z rVert^2 $$
      Is there a specific name for this?










      share|cite|improve this question









      $endgroup$




      I'm a bit new to real analysis. Today, I came across this particular equality, whcih seems obvious to me.
      $$ lVert x + z rVert^2 + lVert x - z rVert^2 = 2 lVert x rVert^2 + 2lVert z rVert^2 $$
      Is there a specific name for this?







      real-analysis






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked 5 hours ago









      JaPJaP

      153




      153






















          1 Answer
          1






          active

          oldest

          votes


















          6












          $begingroup$

          This is the parallelogram law of norms induced by inner products.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you so much!
            $endgroup$
            – JaP
            4 hours ago











          Your Answer





          StackExchange.ifUsing("editor", function () {
          return StackExchange.using("mathjaxEditing", function () {
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          });
          });
          }, "mathjax-editing");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "69"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3154474%2fname-this-simple-norm-equality-real-analysis%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          6












          $begingroup$

          This is the parallelogram law of norms induced by inner products.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you so much!
            $endgroup$
            – JaP
            4 hours ago
















          6












          $begingroup$

          This is the parallelogram law of norms induced by inner products.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you so much!
            $endgroup$
            – JaP
            4 hours ago














          6












          6








          6





          $begingroup$

          This is the parallelogram law of norms induced by inner products.






          share|cite|improve this answer









          $endgroup$



          This is the parallelogram law of norms induced by inner products.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered 5 hours ago









          pulpfictionalpulpfictional

          1786




          1786












          • $begingroup$
            Thank you so much!
            $endgroup$
            – JaP
            4 hours ago


















          • $begingroup$
            Thank you so much!
            $endgroup$
            – JaP
            4 hours ago
















          $begingroup$
          Thank you so much!
          $endgroup$
          – JaP
          4 hours ago




          $begingroup$
          Thank you so much!
          $endgroup$
          – JaP
          4 hours ago


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Mathematics Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          Use MathJax to format equations. MathJax reference.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3154474%2fname-this-simple-norm-equality-real-analysis%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Gersau Kjelder | Navigasjonsmeny46°59′0″N 8°31′0″E46°59′0″N...

          What is the “three and three hundred thousand syndrome”?Who wrote the book Arena?What five creatures were...

          Are all UTXOs locked by an address spent in a transaction?UTXO all sent to change address?Signing...