Finding the angle of a cone from a 3D point












1












$begingroup$


Given a point in $3$D space $(x,y,z)$ and a circular cone about the $x$ axis, I wish to find the angle of the cone such that the point is on the surface of the cone. For a given point, there is only one possible angle (I think). If the point lies in the plane defined by $z$, then the intersection between the plane and the cone is a hyperbola.



This image I found describes the problem fairly well - the plane is traveling along the $x$ axis:
image



The apex of the cone is in the origin $(0,0,0)$, and my point is in $(x,y,z)$, that is, somewhere on the ground. How do I find the angle of the cone such that the point lies on the hyperbola resulting from the intersection of the cone and the ground?










share|cite|improve this question











$endgroup$

















    1












    $begingroup$


    Given a point in $3$D space $(x,y,z)$ and a circular cone about the $x$ axis, I wish to find the angle of the cone such that the point is on the surface of the cone. For a given point, there is only one possible angle (I think). If the point lies in the plane defined by $z$, then the intersection between the plane and the cone is a hyperbola.



    This image I found describes the problem fairly well - the plane is traveling along the $x$ axis:
    image



    The apex of the cone is in the origin $(0,0,0)$, and my point is in $(x,y,z)$, that is, somewhere on the ground. How do I find the angle of the cone such that the point lies on the hyperbola resulting from the intersection of the cone and the ground?










    share|cite|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      Given a point in $3$D space $(x,y,z)$ and a circular cone about the $x$ axis, I wish to find the angle of the cone such that the point is on the surface of the cone. For a given point, there is only one possible angle (I think). If the point lies in the plane defined by $z$, then the intersection between the plane and the cone is a hyperbola.



      This image I found describes the problem fairly well - the plane is traveling along the $x$ axis:
      image



      The apex of the cone is in the origin $(0,0,0)$, and my point is in $(x,y,z)$, that is, somewhere on the ground. How do I find the angle of the cone such that the point lies on the hyperbola resulting from the intersection of the cone and the ground?










      share|cite|improve this question











      $endgroup$




      Given a point in $3$D space $(x,y,z)$ and a circular cone about the $x$ axis, I wish to find the angle of the cone such that the point is on the surface of the cone. For a given point, there is only one possible angle (I think). If the point lies in the plane defined by $z$, then the intersection between the plane and the cone is a hyperbola.



      This image I found describes the problem fairly well - the plane is traveling along the $x$ axis:
      image



      The apex of the cone is in the origin $(0,0,0)$, and my point is in $(x,y,z)$, that is, somewhere on the ground. How do I find the angle of the cone such that the point lies on the hyperbola resulting from the intersection of the cone and the ground?







      geometry






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Feb 10 at 22:01









      Glorfindel

      3,41981830




      3,41981830










      asked May 21 '14 at 9:14









      DhiDhi

      62




      62






















          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          I think I found a solution.



          The point $(x,y,z)$ is not only on the hyperbola, but also on the circle that results from intersecting the cone with the plane defined by $x$ and that is given by the equation $y^2+z^2=r^2$, where $r=sqrt{y^2+z^2}$ is the radius of the circle, which has its center in $(x, 0, 0)$.



          Now that I have the radius $r$ and length of the cone $x$, I can find the angle of the cone $alpha=arctan(r/x)$, which was what I was looking for.



          Tl;dr: $alpha=arctan(sqrt{y^2+z^2}/x)$.






          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%2f803874%2ffinding-the-angle-of-a-cone-from-a-3d-point%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









            0












            $begingroup$

            I think I found a solution.



            The point $(x,y,z)$ is not only on the hyperbola, but also on the circle that results from intersecting the cone with the plane defined by $x$ and that is given by the equation $y^2+z^2=r^2$, where $r=sqrt{y^2+z^2}$ is the radius of the circle, which has its center in $(x, 0, 0)$.



            Now that I have the radius $r$ and length of the cone $x$, I can find the angle of the cone $alpha=arctan(r/x)$, which was what I was looking for.



            Tl;dr: $alpha=arctan(sqrt{y^2+z^2}/x)$.






            share|cite|improve this answer









            $endgroup$


















              0












              $begingroup$

              I think I found a solution.



              The point $(x,y,z)$ is not only on the hyperbola, but also on the circle that results from intersecting the cone with the plane defined by $x$ and that is given by the equation $y^2+z^2=r^2$, where $r=sqrt{y^2+z^2}$ is the radius of the circle, which has its center in $(x, 0, 0)$.



              Now that I have the radius $r$ and length of the cone $x$, I can find the angle of the cone $alpha=arctan(r/x)$, which was what I was looking for.



              Tl;dr: $alpha=arctan(sqrt{y^2+z^2}/x)$.






              share|cite|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                I think I found a solution.



                The point $(x,y,z)$ is not only on the hyperbola, but also on the circle that results from intersecting the cone with the plane defined by $x$ and that is given by the equation $y^2+z^2=r^2$, where $r=sqrt{y^2+z^2}$ is the radius of the circle, which has its center in $(x, 0, 0)$.



                Now that I have the radius $r$ and length of the cone $x$, I can find the angle of the cone $alpha=arctan(r/x)$, which was what I was looking for.



                Tl;dr: $alpha=arctan(sqrt{y^2+z^2}/x)$.






                share|cite|improve this answer









                $endgroup$



                I think I found a solution.



                The point $(x,y,z)$ is not only on the hyperbola, but also on the circle that results from intersecting the cone with the plane defined by $x$ and that is given by the equation $y^2+z^2=r^2$, where $r=sqrt{y^2+z^2}$ is the radius of the circle, which has its center in $(x, 0, 0)$.



                Now that I have the radius $r$ and length of the cone $x$, I can find the angle of the cone $alpha=arctan(r/x)$, which was what I was looking for.



                Tl;dr: $alpha=arctan(sqrt{y^2+z^2}/x)$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered May 22 '14 at 7:18









                DhiDhi

                62




                62






























                    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%2f803874%2ffinding-the-angle-of-a-cone-from-a-3d-point%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

                    MongoDB - Not Authorized To Execute Command

                    in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

                    Npm cannot find a required file even through it is in the searched directory