Average Value - Graphs












0












$begingroup$


enter image description here



long method: Determine an equation for each and solve using average value formula



alternative methods?



How could you prove the average value to be C over an interval [a,b] if you are given a graph.... looking for most efficient/unique methods.










share|cite|improve this question











$endgroup$












  • $begingroup$
    In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
    $endgroup$
    – user157321
    Jul 30 '14 at 12:58
















0












$begingroup$


enter image description here



long method: Determine an equation for each and solve using average value formula



alternative methods?



How could you prove the average value to be C over an interval [a,b] if you are given a graph.... looking for most efficient/unique methods.










share|cite|improve this question











$endgroup$












  • $begingroup$
    In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
    $endgroup$
    – user157321
    Jul 30 '14 at 12:58














0












0








0





$begingroup$


enter image description here



long method: Determine an equation for each and solve using average value formula



alternative methods?



How could you prove the average value to be C over an interval [a,b] if you are given a graph.... looking for most efficient/unique methods.










share|cite|improve this question











$endgroup$




enter image description here



long method: Determine an equation for each and solve using average value formula



alternative methods?



How could you prove the average value to be C over an interval [a,b] if you are given a graph.... looking for most efficient/unique methods.







calculus integration algebra-precalculus definite-integrals






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jul 30 '14 at 12:57









apnorton

15.2k33796




15.2k33796










asked Jul 30 '14 at 12:48









confusedconfused

40821019




40821019












  • $begingroup$
    In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
    $endgroup$
    – user157321
    Jul 30 '14 at 12:58


















  • $begingroup$
    In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
    $endgroup$
    – user157321
    Jul 30 '14 at 12:58
















$begingroup$
In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
$endgroup$
– user157321
Jul 30 '14 at 12:58




$begingroup$
In general you would integrate the function (to find the area below the curve) and divide by the length of the interval ($b-a=6$ here) but I think what is expected here is just to use a bit of guesswork: graph A clearly has an average $>2$, whereas by computing the area of triangles you can find that the average of C and D are 2 and 4 respectively. To show that B has $>2$, just draw the triangle {(0,0),(6,0),(3,4)} : it is contained in the area of the curve and has area =2
$endgroup$
– user157321
Jul 30 '14 at 12:58










2 Answers
2






active

oldest

votes


















0












$begingroup$

Your equation for this question is:



$$frac{1}{6}*int_0^6 h(x) = 2$$



Therefore,



$$int_0^6 h(x) = 12$$



For answers $c$ and $d$ you can use the area of a triangle,



If you try answer choice $c$,



We get that:



$$A = frac{1}{2}*4.5*6 - frac{1}{2}*1.5*(-2) = 12$$



Therefore our answer is C.






share|cite|improve this answer









$endgroup$





















    0












    $begingroup$

    Graph A:
    The part for $xin[0,2)$ compensates with the part for $xin (2,4]$, giving an average of 2 over the interval $[0,4]$. But the part for $xin(4,6]$ is above the line $y=2$. So A is not good.



    GraphB:
    Define a new function $g$ whose graph is composed of one straight line between $(0,0)$ and $(3,4)$ and the other straight line between $(3,4)$ and $(6,0)$. Similarly as in case A, we can see average of the function $g$ is equal to 2. But the graph of $f$ is always above $g$. So B is not good.



    Similarly, we find average in graph C is 2 and average in Graph D is 4






    share|cite|improve this answer









    $endgroup$













      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%2f882590%2faverage-value-graphs%23new-answer', 'question_page');
      }
      );

      Post as a guest















      Required, but never shown

























      2 Answers
      2






      active

      oldest

      votes








      2 Answers
      2






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      0












      $begingroup$

      Your equation for this question is:



      $$frac{1}{6}*int_0^6 h(x) = 2$$



      Therefore,



      $$int_0^6 h(x) = 12$$



      For answers $c$ and $d$ you can use the area of a triangle,



      If you try answer choice $c$,



      We get that:



      $$A = frac{1}{2}*4.5*6 - frac{1}{2}*1.5*(-2) = 12$$



      Therefore our answer is C.






      share|cite|improve this answer









      $endgroup$


















        0












        $begingroup$

        Your equation for this question is:



        $$frac{1}{6}*int_0^6 h(x) = 2$$



        Therefore,



        $$int_0^6 h(x) = 12$$



        For answers $c$ and $d$ you can use the area of a triangle,



        If you try answer choice $c$,



        We get that:



        $$A = frac{1}{2}*4.5*6 - frac{1}{2}*1.5*(-2) = 12$$



        Therefore our answer is C.






        share|cite|improve this answer









        $endgroup$
















          0












          0








          0





          $begingroup$

          Your equation for this question is:



          $$frac{1}{6}*int_0^6 h(x) = 2$$



          Therefore,



          $$int_0^6 h(x) = 12$$



          For answers $c$ and $d$ you can use the area of a triangle,



          If you try answer choice $c$,



          We get that:



          $$A = frac{1}{2}*4.5*6 - frac{1}{2}*1.5*(-2) = 12$$



          Therefore our answer is C.






          share|cite|improve this answer









          $endgroup$



          Your equation for this question is:



          $$frac{1}{6}*int_0^6 h(x) = 2$$



          Therefore,



          $$int_0^6 h(x) = 12$$



          For answers $c$ and $d$ you can use the area of a triangle,



          If you try answer choice $c$,



          We get that:



          $$A = frac{1}{2}*4.5*6 - frac{1}{2}*1.5*(-2) = 12$$



          Therefore our answer is C.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jul 30 '14 at 12:55









          Varun IyerVarun Iyer

          5,317826




          5,317826























              0












              $begingroup$

              Graph A:
              The part for $xin[0,2)$ compensates with the part for $xin (2,4]$, giving an average of 2 over the interval $[0,4]$. But the part for $xin(4,6]$ is above the line $y=2$. So A is not good.



              GraphB:
              Define a new function $g$ whose graph is composed of one straight line between $(0,0)$ and $(3,4)$ and the other straight line between $(3,4)$ and $(6,0)$. Similarly as in case A, we can see average of the function $g$ is equal to 2. But the graph of $f$ is always above $g$. So B is not good.



              Similarly, we find average in graph C is 2 and average in Graph D is 4






              share|cite|improve this answer









              $endgroup$


















                0












                $begingroup$

                Graph A:
                The part for $xin[0,2)$ compensates with the part for $xin (2,4]$, giving an average of 2 over the interval $[0,4]$. But the part for $xin(4,6]$ is above the line $y=2$. So A is not good.



                GraphB:
                Define a new function $g$ whose graph is composed of one straight line between $(0,0)$ and $(3,4)$ and the other straight line between $(3,4)$ and $(6,0)$. Similarly as in case A, we can see average of the function $g$ is equal to 2. But the graph of $f$ is always above $g$. So B is not good.



                Similarly, we find average in graph C is 2 and average in Graph D is 4






                share|cite|improve this answer









                $endgroup$
















                  0












                  0








                  0





                  $begingroup$

                  Graph A:
                  The part for $xin[0,2)$ compensates with the part for $xin (2,4]$, giving an average of 2 over the interval $[0,4]$. But the part for $xin(4,6]$ is above the line $y=2$. So A is not good.



                  GraphB:
                  Define a new function $g$ whose graph is composed of one straight line between $(0,0)$ and $(3,4)$ and the other straight line between $(3,4)$ and $(6,0)$. Similarly as in case A, we can see average of the function $g$ is equal to 2. But the graph of $f$ is always above $g$. So B is not good.



                  Similarly, we find average in graph C is 2 and average in Graph D is 4






                  share|cite|improve this answer









                  $endgroup$



                  Graph A:
                  The part for $xin[0,2)$ compensates with the part for $xin (2,4]$, giving an average of 2 over the interval $[0,4]$. But the part for $xin(4,6]$ is above the line $y=2$. So A is not good.



                  GraphB:
                  Define a new function $g$ whose graph is composed of one straight line between $(0,0)$ and $(3,4)$ and the other straight line between $(3,4)$ and $(6,0)$. Similarly as in case A, we can see average of the function $g$ is equal to 2. But the graph of $f$ is always above $g$. So B is not good.



                  Similarly, we find average in graph C is 2 and average in Graph D is 4







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Jul 30 '14 at 13:01









                  Petite EtincellePetite Etincelle

                  12.4k12148




                  12.4k12148






























                      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%2f882590%2faverage-value-graphs%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

                      Human spaceflight

                      Can not write log (Is /dev/pts mounted?) - openpty in Ubuntu-on-Windows?

                      張江高科駅