Find functions f & g such that f(x+y)=g (x.y) for all x & y?How do you define functions for...

Can fracking help reduce CO2?

Please, smoke with good manners

Why does nature favour the Laplacian?

Why does Bran Stark feel that Jon Snow "needs to know" about his lineage?

Is it possible to Ready a spell to be cast just before the start of your next turn by having the trigger be an ally's attack?

How to stop co-workers from teasing me because I know Russian?

Is it possible to measure lightning discharges as Nikola Tesla?

Is creating your own "experiment" considered cheating during a physics exam?

Confused by notation of atomic number Z and mass number A on periodic table of elements

Transfer over $10k

Why does the Betti number give the measure of k-dimensional holes?

Are some sounds more pleasing to the ear, like ㄴ and ㅁ?

Morally unwholesome deeds knowing the consequences but without unwholesome intentions

"ne paelici suspectaretur" (Tacitus)

Why do Ichisongas hate elephants and hippos?

How to create an ad-hoc wireless network in Ubuntu

Examples of non trivial equivalence relations , I mean equivalence relations without the expression " same ... as" in their definition?

How do I tell my manager that he's wrong?

Confusion about capacitors

Will tsunami waves travel forever if there was no land?

Do I have an "anti-research" personality?

Past Perfect Tense

Were there two appearances of Stan Lee?

Where did the extra Pym particles come from in Endgame?



Find functions f & g such that f(x+y)=g (x.y) for all x & y?


How do you define functions for non-mathematicians?Automated generation of a parametric plot?For each $y in mathbb{R}$ either no $x$ with $f(x) = y$ or two such values of $x$. Show that $f$ is discontinuous.Show that if $C(K)$ is separable, then $K$ is metrisable, for $K$ compact and HausdorffFinding Conjugate harmonic of $u = frac{1}{2} ln(x^2 + y^2)$Asymptotic functions with derivatives that are $1/2^x$Nowhere Differentiable function over a non-compact spaceMethod for deconstructing an integral involving two functionsFinding derivative given $f(x)$ and limitfix point solution or approximation available? logistic regression?













2












$begingroup$


My approach towards this question was that first I putted x=0 and then y=0 which yields f(x)=f(y)and f(x)=g(0), and again for x=1 & y=1 it gives g (x)=f(1+x), and so on. My query is that what should the compact & rigorous form of proof or solution looks like because I found myself stuck between results and not comprehending results very well. Thanks.










share|cite|improve this question











$endgroup$

















    2












    $begingroup$


    My approach towards this question was that first I putted x=0 and then y=0 which yields f(x)=f(y)and f(x)=g(0), and again for x=1 & y=1 it gives g (x)=f(1+x), and so on. My query is that what should the compact & rigorous form of proof or solution looks like because I found myself stuck between results and not comprehending results very well. Thanks.










    share|cite|improve this question











    $endgroup$















      2












      2








      2


      1



      $begingroup$


      My approach towards this question was that first I putted x=0 and then y=0 which yields f(x)=f(y)and f(x)=g(0), and again for x=1 & y=1 it gives g (x)=f(1+x), and so on. My query is that what should the compact & rigorous form of proof or solution looks like because I found myself stuck between results and not comprehending results very well. Thanks.










      share|cite|improve this question











      $endgroup$




      My approach towards this question was that first I putted x=0 and then y=0 which yields f(x)=f(y)and f(x)=g(0), and again for x=1 & y=1 it gives g (x)=f(1+x), and so on. My query is that what should the compact & rigorous form of proof or solution looks like because I found myself stuck between results and not comprehending results very well. Thanks.







      real-analysis calculus functional-analysis functions






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited 1 hour ago







      BORN TO LEARN

















      asked 2 hours ago









      BORN TO LEARNBORN TO LEARN

      377




      377






















          1 Answer
          1






          active

          oldest

          votes


















          4












          $begingroup$

          $$f(x) = f(x + 0) = g(x cdot 0) = g(0)$$ for all $x$. Thus $f(x)$ is constant and always equal to $g(0)$. Moreover, $$g(0) = f(1 + y) = g(1 cdot y) = g(y)$$ for all $y$. Thus $g$ is also constant and equal to $g(0)$. Thus $f, g$ are the same constant function. All constant functions $f = g = c$ will satisfy the relation. This is all you need.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Yeah thanks man m looking for this kind of preciseness.
            $endgroup$
            – BORN TO LEARN
            2 hours ago










          • $begingroup$
            Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            Now I think your proof also needs editing?
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
            $endgroup$
            – BenB
            1 hour ago






          • 1




            $begingroup$
            @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
            $endgroup$
            – BenB
            1 hour ago












          Your Answer








          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%2f3206426%2ffind-functions-f-g-such-that-fxy-g-x-y-for-all-x-y%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









          4












          $begingroup$

          $$f(x) = f(x + 0) = g(x cdot 0) = g(0)$$ for all $x$. Thus $f(x)$ is constant and always equal to $g(0)$. Moreover, $$g(0) = f(1 + y) = g(1 cdot y) = g(y)$$ for all $y$. Thus $g$ is also constant and equal to $g(0)$. Thus $f, g$ are the same constant function. All constant functions $f = g = c$ will satisfy the relation. This is all you need.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Yeah thanks man m looking for this kind of preciseness.
            $endgroup$
            – BORN TO LEARN
            2 hours ago










          • $begingroup$
            Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            Now I think your proof also needs editing?
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
            $endgroup$
            – BenB
            1 hour ago






          • 1




            $begingroup$
            @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
            $endgroup$
            – BenB
            1 hour ago
















          4












          $begingroup$

          $$f(x) = f(x + 0) = g(x cdot 0) = g(0)$$ for all $x$. Thus $f(x)$ is constant and always equal to $g(0)$. Moreover, $$g(0) = f(1 + y) = g(1 cdot y) = g(y)$$ for all $y$. Thus $g$ is also constant and equal to $g(0)$. Thus $f, g$ are the same constant function. All constant functions $f = g = c$ will satisfy the relation. This is all you need.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Yeah thanks man m looking for this kind of preciseness.
            $endgroup$
            – BORN TO LEARN
            2 hours ago










          • $begingroup$
            Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            Now I think your proof also needs editing?
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
            $endgroup$
            – BenB
            1 hour ago






          • 1




            $begingroup$
            @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
            $endgroup$
            – BenB
            1 hour ago














          4












          4








          4





          $begingroup$

          $$f(x) = f(x + 0) = g(x cdot 0) = g(0)$$ for all $x$. Thus $f(x)$ is constant and always equal to $g(0)$. Moreover, $$g(0) = f(1 + y) = g(1 cdot y) = g(y)$$ for all $y$. Thus $g$ is also constant and equal to $g(0)$. Thus $f, g$ are the same constant function. All constant functions $f = g = c$ will satisfy the relation. This is all you need.






          share|cite|improve this answer









          $endgroup$



          $$f(x) = f(x + 0) = g(x cdot 0) = g(0)$$ for all $x$. Thus $f(x)$ is constant and always equal to $g(0)$. Moreover, $$g(0) = f(1 + y) = g(1 cdot y) = g(y)$$ for all $y$. Thus $g$ is also constant and equal to $g(0)$. Thus $f, g$ are the same constant function. All constant functions $f = g = c$ will satisfy the relation. This is all you need.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered 2 hours ago









          BenBBenB

          46039




          46039








          • 1




            $begingroup$
            Yeah thanks man m looking for this kind of preciseness.
            $endgroup$
            – BORN TO LEARN
            2 hours ago










          • $begingroup$
            Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            Now I think your proof also needs editing?
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
            $endgroup$
            – BenB
            1 hour ago






          • 1




            $begingroup$
            @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
            $endgroup$
            – BenB
            1 hour ago














          • 1




            $begingroup$
            Yeah thanks man m looking for this kind of preciseness.
            $endgroup$
            – BORN TO LEARN
            2 hours ago










          • $begingroup$
            Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            Now I think your proof also needs editing?
            $endgroup$
            – BORN TO LEARN
            1 hour ago










          • $begingroup$
            @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
            $endgroup$
            – BenB
            1 hour ago






          • 1




            $begingroup$
            @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
            $endgroup$
            – BenB
            1 hour ago








          1




          1




          $begingroup$
          Yeah thanks man m looking for this kind of preciseness.
          $endgroup$
          – BORN TO LEARN
          2 hours ago




          $begingroup$
          Yeah thanks man m looking for this kind of preciseness.
          $endgroup$
          – BORN TO LEARN
          2 hours ago












          $begingroup$
          Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
          $endgroup$
          – BORN TO LEARN
          1 hour ago




          $begingroup$
          Sorry I edited it because I made a mistake in description that g(x)=f(1+y) instead of g(x)=f(1+x).
          $endgroup$
          – BORN TO LEARN
          1 hour ago












          $begingroup$
          Now I think your proof also needs editing?
          $endgroup$
          – BORN TO LEARN
          1 hour ago




          $begingroup$
          Now I think your proof also needs editing?
          $endgroup$
          – BORN TO LEARN
          1 hour ago












          $begingroup$
          @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
          $endgroup$
          – BenB
          1 hour ago




          $begingroup$
          @BORNTOLEARN where does it need edited? I only used the relation f(x + y) = g(x y).
          $endgroup$
          – BenB
          1 hour ago




          1




          1




          $begingroup$
          @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
          $endgroup$
          – BenB
          1 hour ago




          $begingroup$
          @BORNTOLEARN because f is identically equal to g(0) as I show in the previous part.
          $endgroup$
          – BenB
          1 hour 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%2f3206426%2ffind-functions-f-g-such-that-fxy-g-x-y-for-all-x-y%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...

          Hestehale Innhaldsliste Hestehale på kvinner | Hestehale på menn | Galleri | Sjå òg |...

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