Coordinate Geometry - Distance Formula












0












$begingroup$


If the points $A(4,3)$ and $B(x,5)$ are on the circle with center $O(2,3)$ find the value of $x$.



Since $AO=BO$
Using distance formula,
we get $x=2$



However my approach was why can't section formula be used where $(2,3)$ can be considered as the midpoint so that
$M = frac{x_1 + x_2}{2}$



I can't figure out the reason why this method doesn't work.
Any help will be appreciated.










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    If the points $A(4,3)$ and $B(x,5)$ are on the circle with center $O(2,3)$ find the value of $x$.



    Since $AO=BO$
    Using distance formula,
    we get $x=2$



    However my approach was why can't section formula be used where $(2,3)$ can be considered as the midpoint so that
    $M = frac{x_1 + x_2}{2}$



    I can't figure out the reason why this method doesn't work.
    Any help will be appreciated.










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      If the points $A(4,3)$ and $B(x,5)$ are on the circle with center $O(2,3)$ find the value of $x$.



      Since $AO=BO$
      Using distance formula,
      we get $x=2$



      However my approach was why can't section formula be used where $(2,3)$ can be considered as the midpoint so that
      $M = frac{x_1 + x_2}{2}$



      I can't figure out the reason why this method doesn't work.
      Any help will be appreciated.










      share|cite|improve this question











      $endgroup$




      If the points $A(4,3)$ and $B(x,5)$ are on the circle with center $O(2,3)$ find the value of $x$.



      Since $AO=BO$
      Using distance formula,
      we get $x=2$



      However my approach was why can't section formula be used where $(2,3)$ can be considered as the midpoint so that
      $M = frac{x_1 + x_2}{2}$



      I can't figure out the reason why this method doesn't work.
      Any help will be appreciated.







      geometry






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 20 '18 at 12:16









      Matko

      864




      864










      asked Dec 20 '18 at 12:00









      Naimisha GirishNaimisha Girish

      14




      14






















          3 Answers
          3






          active

          oldest

          votes


















          3












          $begingroup$

          That would require the line segment $AB$ to be the diameter for $M$ to be equal to $O$ which is not necessarily true.



          It is possible that $AB$ doesn't pass through $O$.






          share|cite|improve this answer









          $endgroup$





















            0












            $begingroup$

            You should sketch it on the cooredinate plane.



            $hspace{3cm}$![enter image description here



            If $A(4,3)$ lies on the circle with center $O(2,3)$, then $AO=2$ is the radius.



            The point $B(x,5)$ lies somewhere on the blue line $y=5$. In order for $B$ to lie on the circle too, it must be a common (touching or intersection) point of the circle and the blue line. And we see it is the touching point $B(2,5)$.



            When you consider $M(2,3)$ as the middle point of $AB$ and calculate $frac{x_1+x_2}{2}=frac{4+x}{2}=2 Rightarrow x=0$, you will find the point $C(0,3)$ which is on the circle, but it is not on the blue line. Also, $frac{y_1+y_2}{2}=frac{3+5}{2}=4ne 3$.






            share|cite|improve this answer









            $endgroup$





















              0












              $begingroup$

              Note : $AB$ is a chord.



              Midpoint: $M=(x/2+2,,4)$.



              1) Slope $AB$:



              $m_1:= dfrac{5-3}{x-4}=dfrac{2}{x-4}$.



              2) Slope $MO$:



              $m_2:= dfrac {4-3}{x/2+2 -2}=2/x.$



              $m_1$ is perpendicular to $m_2$ (why?):



              $m_1m_2=-1.$



              Hence $x/2-2=- x/2;$



              $x=2$






              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%2f3047461%2fcoordinate-geometry-distance-formula%23new-answer', 'question_page');
                }
                );

                Post as a guest















                Required, but never shown

























                3 Answers
                3






                active

                oldest

                votes








                3 Answers
                3






                active

                oldest

                votes









                active

                oldest

                votes






                active

                oldest

                votes









                3












                $begingroup$

                That would require the line segment $AB$ to be the diameter for $M$ to be equal to $O$ which is not necessarily true.



                It is possible that $AB$ doesn't pass through $O$.






                share|cite|improve this answer









                $endgroup$


















                  3












                  $begingroup$

                  That would require the line segment $AB$ to be the diameter for $M$ to be equal to $O$ which is not necessarily true.



                  It is possible that $AB$ doesn't pass through $O$.






                  share|cite|improve this answer









                  $endgroup$
















                    3












                    3








                    3





                    $begingroup$

                    That would require the line segment $AB$ to be the diameter for $M$ to be equal to $O$ which is not necessarily true.



                    It is possible that $AB$ doesn't pass through $O$.






                    share|cite|improve this answer









                    $endgroup$



                    That would require the line segment $AB$ to be the diameter for $M$ to be equal to $O$ which is not necessarily true.



                    It is possible that $AB$ doesn't pass through $O$.







                    share|cite|improve this answer












                    share|cite|improve this answer



                    share|cite|improve this answer










                    answered Dec 20 '18 at 12:12









                    Siong Thye GohSiong Thye Goh

                    101k1466118




                    101k1466118























                        0












                        $begingroup$

                        You should sketch it on the cooredinate plane.



                        $hspace{3cm}$![enter image description here



                        If $A(4,3)$ lies on the circle with center $O(2,3)$, then $AO=2$ is the radius.



                        The point $B(x,5)$ lies somewhere on the blue line $y=5$. In order for $B$ to lie on the circle too, it must be a common (touching or intersection) point of the circle and the blue line. And we see it is the touching point $B(2,5)$.



                        When you consider $M(2,3)$ as the middle point of $AB$ and calculate $frac{x_1+x_2}{2}=frac{4+x}{2}=2 Rightarrow x=0$, you will find the point $C(0,3)$ which is on the circle, but it is not on the blue line. Also, $frac{y_1+y_2}{2}=frac{3+5}{2}=4ne 3$.






                        share|cite|improve this answer









                        $endgroup$


















                          0












                          $begingroup$

                          You should sketch it on the cooredinate plane.



                          $hspace{3cm}$![enter image description here



                          If $A(4,3)$ lies on the circle with center $O(2,3)$, then $AO=2$ is the radius.



                          The point $B(x,5)$ lies somewhere on the blue line $y=5$. In order for $B$ to lie on the circle too, it must be a common (touching or intersection) point of the circle and the blue line. And we see it is the touching point $B(2,5)$.



                          When you consider $M(2,3)$ as the middle point of $AB$ and calculate $frac{x_1+x_2}{2}=frac{4+x}{2}=2 Rightarrow x=0$, you will find the point $C(0,3)$ which is on the circle, but it is not on the blue line. Also, $frac{y_1+y_2}{2}=frac{3+5}{2}=4ne 3$.






                          share|cite|improve this answer









                          $endgroup$
















                            0












                            0








                            0





                            $begingroup$

                            You should sketch it on the cooredinate plane.



                            $hspace{3cm}$![enter image description here



                            If $A(4,3)$ lies on the circle with center $O(2,3)$, then $AO=2$ is the radius.



                            The point $B(x,5)$ lies somewhere on the blue line $y=5$. In order for $B$ to lie on the circle too, it must be a common (touching or intersection) point of the circle and the blue line. And we see it is the touching point $B(2,5)$.



                            When you consider $M(2,3)$ as the middle point of $AB$ and calculate $frac{x_1+x_2}{2}=frac{4+x}{2}=2 Rightarrow x=0$, you will find the point $C(0,3)$ which is on the circle, but it is not on the blue line. Also, $frac{y_1+y_2}{2}=frac{3+5}{2}=4ne 3$.






                            share|cite|improve this answer









                            $endgroup$



                            You should sketch it on the cooredinate plane.



                            $hspace{3cm}$![enter image description here



                            If $A(4,3)$ lies on the circle with center $O(2,3)$, then $AO=2$ is the radius.



                            The point $B(x,5)$ lies somewhere on the blue line $y=5$. In order for $B$ to lie on the circle too, it must be a common (touching or intersection) point of the circle and the blue line. And we see it is the touching point $B(2,5)$.



                            When you consider $M(2,3)$ as the middle point of $AB$ and calculate $frac{x_1+x_2}{2}=frac{4+x}{2}=2 Rightarrow x=0$, you will find the point $C(0,3)$ which is on the circle, but it is not on the blue line. Also, $frac{y_1+y_2}{2}=frac{3+5}{2}=4ne 3$.







                            share|cite|improve this answer












                            share|cite|improve this answer



                            share|cite|improve this answer










                            answered Dec 20 '18 at 13:31









                            farruhotafarruhota

                            20.3k2739




                            20.3k2739























                                0












                                $begingroup$

                                Note : $AB$ is a chord.



                                Midpoint: $M=(x/2+2,,4)$.



                                1) Slope $AB$:



                                $m_1:= dfrac{5-3}{x-4}=dfrac{2}{x-4}$.



                                2) Slope $MO$:



                                $m_2:= dfrac {4-3}{x/2+2 -2}=2/x.$



                                $m_1$ is perpendicular to $m_2$ (why?):



                                $m_1m_2=-1.$



                                Hence $x/2-2=- x/2;$



                                $x=2$






                                share|cite|improve this answer











                                $endgroup$


















                                  0












                                  $begingroup$

                                  Note : $AB$ is a chord.



                                  Midpoint: $M=(x/2+2,,4)$.



                                  1) Slope $AB$:



                                  $m_1:= dfrac{5-3}{x-4}=dfrac{2}{x-4}$.



                                  2) Slope $MO$:



                                  $m_2:= dfrac {4-3}{x/2+2 -2}=2/x.$



                                  $m_1$ is perpendicular to $m_2$ (why?):



                                  $m_1m_2=-1.$



                                  Hence $x/2-2=- x/2;$



                                  $x=2$






                                  share|cite|improve this answer











                                  $endgroup$
















                                    0












                                    0








                                    0





                                    $begingroup$

                                    Note : $AB$ is a chord.



                                    Midpoint: $M=(x/2+2,,4)$.



                                    1) Slope $AB$:



                                    $m_1:= dfrac{5-3}{x-4}=dfrac{2}{x-4}$.



                                    2) Slope $MO$:



                                    $m_2:= dfrac {4-3}{x/2+2 -2}=2/x.$



                                    $m_1$ is perpendicular to $m_2$ (why?):



                                    $m_1m_2=-1.$



                                    Hence $x/2-2=- x/2;$



                                    $x=2$






                                    share|cite|improve this answer











                                    $endgroup$



                                    Note : $AB$ is a chord.



                                    Midpoint: $M=(x/2+2,,4)$.



                                    1) Slope $AB$:



                                    $m_1:= dfrac{5-3}{x-4}=dfrac{2}{x-4}$.



                                    2) Slope $MO$:



                                    $m_2:= dfrac {4-3}{x/2+2 -2}=2/x.$



                                    $m_1$ is perpendicular to $m_2$ (why?):



                                    $m_1m_2=-1.$



                                    Hence $x/2-2=- x/2;$



                                    $x=2$







                                    share|cite|improve this answer














                                    share|cite|improve this answer



                                    share|cite|improve this answer








                                    edited Dec 20 '18 at 15:05

























                                    answered Dec 20 '18 at 13:00









                                    Peter SzilasPeter Szilas

                                    11.3k2822




                                    11.3k2822






























                                        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%2f3047461%2fcoordinate-geometry-distance-formula%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

                                        Quarter-circle Tiles

                                        build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

                                        Mont Emei