Mean Value Theorem Q

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
0
down vote

favorite












If $h(x) = (fcirc g)(x), xin [a,b]$, $f(x)$ and $g(x)$ are continuous over $[a,b]$ and differentiable over $(a,b)$. And $g(a) = b, g(b) = a$. We need to show that there exists at least one $c in (a,b)$ such that
$$h(a)-h(b) = f'(c)(b-a)$$



I tried to use the mean value theorem and I got
$$h(b)-h(a) = h'(c)(b-a)$$



Do you have any suggestions please










share|cite|improve this question





















  • Make use of the condition about $g$.
    – xbh
    Sep 2 at 9:45










  • Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
    – xbh
    Sep 2 at 10:01














up vote
0
down vote

favorite












If $h(x) = (fcirc g)(x), xin [a,b]$, $f(x)$ and $g(x)$ are continuous over $[a,b]$ and differentiable over $(a,b)$. And $g(a) = b, g(b) = a$. We need to show that there exists at least one $c in (a,b)$ such that
$$h(a)-h(b) = f'(c)(b-a)$$



I tried to use the mean value theorem and I got
$$h(b)-h(a) = h'(c)(b-a)$$



Do you have any suggestions please










share|cite|improve this question





















  • Make use of the condition about $g$.
    – xbh
    Sep 2 at 9:45










  • Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
    – xbh
    Sep 2 at 10:01












up vote
0
down vote

favorite









up vote
0
down vote

favorite











If $h(x) = (fcirc g)(x), xin [a,b]$, $f(x)$ and $g(x)$ are continuous over $[a,b]$ and differentiable over $(a,b)$. And $g(a) = b, g(b) = a$. We need to show that there exists at least one $c in (a,b)$ such that
$$h(a)-h(b) = f'(c)(b-a)$$



I tried to use the mean value theorem and I got
$$h(b)-h(a) = h'(c)(b-a)$$



Do you have any suggestions please










share|cite|improve this question













If $h(x) = (fcirc g)(x), xin [a,b]$, $f(x)$ and $g(x)$ are continuous over $[a,b]$ and differentiable over $(a,b)$. And $g(a) = b, g(b) = a$. We need to show that there exists at least one $c in (a,b)$ such that
$$h(a)-h(b) = f'(c)(b-a)$$



I tried to use the mean value theorem and I got
$$h(b)-h(a) = h'(c)(b-a)$$



Do you have any suggestions please







calculus






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Sep 2 at 9:36









Ahmed

1,259511




1,259511











  • Make use of the condition about $g$.
    – xbh
    Sep 2 at 9:45










  • Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
    – xbh
    Sep 2 at 10:01
















  • Make use of the condition about $g$.
    – xbh
    Sep 2 at 9:45










  • Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
    – xbh
    Sep 2 at 10:01















Make use of the condition about $g$.
– xbh
Sep 2 at 9:45




Make use of the condition about $g$.
– xbh
Sep 2 at 9:45












Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
– xbh
Sep 2 at 10:01




Seems that $g([a,b] ) subseteq [a,b] $ is presumed, otherwise $h$ might not be defined.
– xbh
Sep 2 at 10:01










2 Answers
2






active

oldest

votes

















up vote
0
down vote













As I commented, if we assume $g([a,b]) subseteq [a,b]$, then $h$ would be well-defined. Now use the condition about $g$, we write the equation we want to prove as
$$
frac h(a) - h(b) g(a) - g(b) = f'(c).
$$
Now consider Cauchy Mean Value Theorem. If $g'neq 0$ on $[a,b]$ is also presumed, then the equation is easily deduced. Otherwise this question would be much complicated.






share|cite|improve this answer



























    up vote
    0
    down vote













    It was easier than I expected



    I have to apply the Mean Value Theorem on $f(x)$, then



    there exists at least one $c in (a,b)$ such that



    $$f'(c) = fracf(b) - f(a)b-a$$



    Now, since $h(a) = (f circ g) (a) = f(g(a)) = f(b)$



    $h(b) = (f circ g) (b) = f(g(b)) = f(a)$



    then



    $$f'(c) = frach(a) - h(b)b-a$$






    share|cite|improve this answer




















      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',
      convertImagesToLinks: true,
      noModals: false,
      showLowRepImageUploadWarning: true,
      reputationToPostImages: 10,
      bindNavPrevention: true,
      postfix: "",
      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%2f2902531%2fmean-value-theorem-q%23new-answer', 'question_page');

      );

      Post as a guest






























      2 Answers
      2






      active

      oldest

      votes








      2 Answers
      2






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      0
      down vote













      As I commented, if we assume $g([a,b]) subseteq [a,b]$, then $h$ would be well-defined. Now use the condition about $g$, we write the equation we want to prove as
      $$
      frac h(a) - h(b) g(a) - g(b) = f'(c).
      $$
      Now consider Cauchy Mean Value Theorem. If $g'neq 0$ on $[a,b]$ is also presumed, then the equation is easily deduced. Otherwise this question would be much complicated.






      share|cite|improve this answer
























        up vote
        0
        down vote













        As I commented, if we assume $g([a,b]) subseteq [a,b]$, then $h$ would be well-defined. Now use the condition about $g$, we write the equation we want to prove as
        $$
        frac h(a) - h(b) g(a) - g(b) = f'(c).
        $$
        Now consider Cauchy Mean Value Theorem. If $g'neq 0$ on $[a,b]$ is also presumed, then the equation is easily deduced. Otherwise this question would be much complicated.






        share|cite|improve this answer






















          up vote
          0
          down vote










          up vote
          0
          down vote









          As I commented, if we assume $g([a,b]) subseteq [a,b]$, then $h$ would be well-defined. Now use the condition about $g$, we write the equation we want to prove as
          $$
          frac h(a) - h(b) g(a) - g(b) = f'(c).
          $$
          Now consider Cauchy Mean Value Theorem. If $g'neq 0$ on $[a,b]$ is also presumed, then the equation is easily deduced. Otherwise this question would be much complicated.






          share|cite|improve this answer












          As I commented, if we assume $g([a,b]) subseteq [a,b]$, then $h$ would be well-defined. Now use the condition about $g$, we write the equation we want to prove as
          $$
          frac h(a) - h(b) g(a) - g(b) = f'(c).
          $$
          Now consider Cauchy Mean Value Theorem. If $g'neq 0$ on $[a,b]$ is also presumed, then the equation is easily deduced. Otherwise this question would be much complicated.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Sep 2 at 10:06









          xbh

          3,515320




          3,515320




















              up vote
              0
              down vote













              It was easier than I expected



              I have to apply the Mean Value Theorem on $f(x)$, then



              there exists at least one $c in (a,b)$ such that



              $$f'(c) = fracf(b) - f(a)b-a$$



              Now, since $h(a) = (f circ g) (a) = f(g(a)) = f(b)$



              $h(b) = (f circ g) (b) = f(g(b)) = f(a)$



              then



              $$f'(c) = frach(a) - h(b)b-a$$






              share|cite|improve this answer
























                up vote
                0
                down vote













                It was easier than I expected



                I have to apply the Mean Value Theorem on $f(x)$, then



                there exists at least one $c in (a,b)$ such that



                $$f'(c) = fracf(b) - f(a)b-a$$



                Now, since $h(a) = (f circ g) (a) = f(g(a)) = f(b)$



                $h(b) = (f circ g) (b) = f(g(b)) = f(a)$



                then



                $$f'(c) = frach(a) - h(b)b-a$$






                share|cite|improve this answer






















                  up vote
                  0
                  down vote










                  up vote
                  0
                  down vote









                  It was easier than I expected



                  I have to apply the Mean Value Theorem on $f(x)$, then



                  there exists at least one $c in (a,b)$ such that



                  $$f'(c) = fracf(b) - f(a)b-a$$



                  Now, since $h(a) = (f circ g) (a) = f(g(a)) = f(b)$



                  $h(b) = (f circ g) (b) = f(g(b)) = f(a)$



                  then



                  $$f'(c) = frach(a) - h(b)b-a$$






                  share|cite|improve this answer












                  It was easier than I expected



                  I have to apply the Mean Value Theorem on $f(x)$, then



                  there exists at least one $c in (a,b)$ such that



                  $$f'(c) = fracf(b) - f(a)b-a$$



                  Now, since $h(a) = (f circ g) (a) = f(g(a)) = f(b)$



                  $h(b) = (f circ g) (b) = f(g(b)) = f(a)$



                  then



                  $$f'(c) = frach(a) - h(b)b-a$$







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Sep 2 at 14:51









                  Ahmed

                  1,259511




                  1,259511



























                       

                      draft saved


                      draft discarded















































                       


                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function ()
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2902531%2fmean-value-theorem-q%23new-answer', 'question_page');

                      );

                      Post as a guest













































































                      這個網誌中的熱門文章

                      Is there any way to eliminate the singular point to solve this integral by hand or by approximations?

                      Why am i infinitely getting the same tweet with the Twitter Search API?

                      Amount of Number Combinations to Reach a Sum of 10 With Integers 1-9 Using 2 or More Integers [closed]