Geometrical Applications of Complex Numbers












1












$begingroup$



The complex numbers $z_1,z_2,z_3$ satisfying $$dfrac{z_1+z_3}{z_2-z_3}=dfrac{1-isqrt{3}}{2}$$ are the vertices of a triangle which is:



a) of area $0$



b) equilateral



c) right angled and isosceles



d) obtuse angled




$$$$



All I got was that from the Rotation Theorem, $$argleft(dfrac{z_1+z_3}{z_2-z_3}right)=-pi/3$$ and that $$|z_1+z_3|=|z_2-z_3|$$
$$$$
Could somebody please show me how to solve this problem? Many thanks!






calculus complex-analysis algebra-precalculus geometry complex-numbers







share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
    $endgroup$
    – grand_chat
    Mar 25 '16 at 7:04










  • $begingroup$
    Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
    $endgroup$
    – mea43
    Mar 25 '16 at 7:10












  • $begingroup$
    You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
    $endgroup$
    – Eddy Khemiri
    Mar 25 '16 at 10:36










  • $begingroup$
    @mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
    $endgroup$
    – Better World
    Mar 25 '16 at 11:01












  • $begingroup$
    @EddyKhemiri Edited, thanks for informing me.
    $endgroup$
    – Better World
    Mar 25 '16 at 11:03


















1












$begingroup$



The complex numbers $z_1,z_2,z_3$ satisfying $$dfrac{z_1+z_3}{z_2-z_3}=dfrac{1-isqrt{3}}{2}$$ are the vertices of a triangle which is:



a) of area $0$



b) equilateral



c) right angled and isosceles



d) obtuse angled




$$$$



All I got was that from the Rotation Theorem, $$argleft(dfrac{z_1+z_3}{z_2-z_3}right)=-pi/3$$ and that $$|z_1+z_3|=|z_2-z_3|$$
$$$$
Could somebody please show me how to solve this problem? Many thanks!






calculus complex-analysis algebra-precalculus geometry complex-numbers







share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
    $endgroup$
    – grand_chat
    Mar 25 '16 at 7:04










  • $begingroup$
    Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
    $endgroup$
    – mea43
    Mar 25 '16 at 7:10












  • $begingroup$
    You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
    $endgroup$
    – Eddy Khemiri
    Mar 25 '16 at 10:36










  • $begingroup$
    @mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
    $endgroup$
    – Better World
    Mar 25 '16 at 11:01












  • $begingroup$
    @EddyKhemiri Edited, thanks for informing me.
    $endgroup$
    – Better World
    Mar 25 '16 at 11:03
















1












1








1


2



$begingroup$



The complex numbers $z_1,z_2,z_3$ satisfying $$dfrac{z_1+z_3}{z_2-z_3}=dfrac{1-isqrt{3}}{2}$$ are the vertices of a triangle which is:



a) of area $0$



b) equilateral



c) right angled and isosceles



d) obtuse angled




$$$$



All I got was that from the Rotation Theorem, $$argleft(dfrac{z_1+z_3}{z_2-z_3}right)=-pi/3$$ and that $$|z_1+z_3|=|z_2-z_3|$$
$$$$
Could somebody please show me how to solve this problem? Many thanks!






calculus complex-analysis algebra-precalculus geometry complex-numbers







share|cite|improve this question











$endgroup$





The complex numbers $z_1,z_2,z_3$ satisfying $$dfrac{z_1+z_3}{z_2-z_3}=dfrac{1-isqrt{3}}{2}$$ are the vertices of a triangle which is:



a) of area $0$



b) equilateral



c) right angled and isosceles



d) obtuse angled




$$$$



All I got was that from the Rotation Theorem, $$argleft(dfrac{z_1+z_3}{z_2-z_3}right)=-pi/3$$ and that $$|z_1+z_3|=|z_2-z_3|$$
$$$$
Could somebody please show me how to solve this problem? Many thanks!






calculus complex-analysis algebra-precalculus geometry complex-numbers




calculus complex-analysis algebra-precalculus geometry complex-numbers






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 6 '18 at 11:13









user376343

3,3582826




3,3582826










asked Mar 25 '16 at 6:17









Better WorldBetter World

10038




10038








  • 1




    $begingroup$
    If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
    $endgroup$
    – grand_chat
    Mar 25 '16 at 7:04










  • $begingroup$
    Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
    $endgroup$
    – mea43
    Mar 25 '16 at 7:10












  • $begingroup$
    You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
    $endgroup$
    – Eddy Khemiri
    Mar 25 '16 at 10:36










  • $begingroup$
    @mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
    $endgroup$
    – Better World
    Mar 25 '16 at 11:01












  • $begingroup$
    @EddyKhemiri Edited, thanks for informing me.
    $endgroup$
    – Better World
    Mar 25 '16 at 11:03
















  • 1




    $begingroup$
    If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
    $endgroup$
    – grand_chat
    Mar 25 '16 at 7:04










  • $begingroup$
    Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
    $endgroup$
    – mea43
    Mar 25 '16 at 7:10












  • $begingroup$
    You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
    $endgroup$
    – Eddy Khemiri
    Mar 25 '16 at 10:36










  • $begingroup$
    @mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
    $endgroup$
    – Better World
    Mar 25 '16 at 11:01












  • $begingroup$
    @EddyKhemiri Edited, thanks for informing me.
    $endgroup$
    – Better World
    Mar 25 '16 at 11:03










1




1




$begingroup$
If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
$endgroup$
– grand_chat
Mar 25 '16 at 7:04




$begingroup$
If the numerator were $z_1-z_3$ instead of $z_1+z_3$, then the answer would be (b), because the information you're given would imply that two of the sides have equal length and the angle between those two sides is $60^circ$.
$endgroup$
– grand_chat
Mar 25 '16 at 7:04












$begingroup$
Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
$endgroup$
– mea43
Mar 25 '16 at 7:10






$begingroup$
Hint: Shift the origin to any of $z_1, z_2, z_3$ to see the properties of triangle, as angles and sides are invariant under translation of origin.
$endgroup$
– mea43
Mar 25 '16 at 7:10














$begingroup$
You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
$endgroup$
– Eddy Khemiri
Mar 25 '16 at 10:36




$begingroup$
You should edit your post: in fact it's $frac{text{z1}+text{z3}}{text{z2}-text{z3}}=e^{-ifrac{pi }{3}}$ and $arg left(frac{text{z1}+text{z3}}{text{z2}-text{z3}}right)=-frac{pi }{3}$. As @user21820, I don't think you can know much more about $z1,z2,z3$...
$endgroup$
– Eddy Khemiri
Mar 25 '16 at 10:36












$begingroup$
@mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
$endgroup$
– Better World
Mar 25 '16 at 11:01






$begingroup$
@mea43 Sir I tried for very long, but couldn't reach anywhere. Could you please help me?
$endgroup$
– Better World
Mar 25 '16 at 11:01














$begingroup$
@EddyKhemiri Edited, thanks for informing me.
$endgroup$
– Better World
Mar 25 '16 at 11:03






$begingroup$
@EddyKhemiri Edited, thanks for informing me.
$endgroup$
– Better World
Mar 25 '16 at 11:03












1 Answer
1






active

oldest

votes


















1












$begingroup$

There is a problem with the problem. By what you have stated, we know that $(-z_1,z_2,z_3)$ are the vertices of an isosceles triangle with equal sides meeting at $120^circ$. But then we don't know anything much about $(z_1,z_2,z_3)$, because as you can see translating $(-z_1,z_2,z_3)$ around makes $(z_1,z_2,z_3)$ change shape.






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%2f1712635%2fgeometrical-applications-of-complex-numbers%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









    1












    $begingroup$

    There is a problem with the problem. By what you have stated, we know that $(-z_1,z_2,z_3)$ are the vertices of an isosceles triangle with equal sides meeting at $120^circ$. But then we don't know anything much about $(z_1,z_2,z_3)$, because as you can see translating $(-z_1,z_2,z_3)$ around makes $(z_1,z_2,z_3)$ change shape.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      There is a problem with the problem. By what you have stated, we know that $(-z_1,z_2,z_3)$ are the vertices of an isosceles triangle with equal sides meeting at $120^circ$. But then we don't know anything much about $(z_1,z_2,z_3)$, because as you can see translating $(-z_1,z_2,z_3)$ around makes $(z_1,z_2,z_3)$ change shape.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        There is a problem with the problem. By what you have stated, we know that $(-z_1,z_2,z_3)$ are the vertices of an isosceles triangle with equal sides meeting at $120^circ$. But then we don't know anything much about $(z_1,z_2,z_3)$, because as you can see translating $(-z_1,z_2,z_3)$ around makes $(z_1,z_2,z_3)$ change shape.






        share|cite|improve this answer









        $endgroup$



        There is a problem with the problem. By what you have stated, we know that $(-z_1,z_2,z_3)$ are the vertices of an isosceles triangle with equal sides meeting at $120^circ$. But then we don't know anything much about $(z_1,z_2,z_3)$, because as you can see translating $(-z_1,z_2,z_3)$ around makes $(z_1,z_2,z_3)$ change shape.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Mar 25 '16 at 9:09









        user21820user21820

        38.8k543153




        38.8k543153






























            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%2f1712635%2fgeometrical-applications-of-complex-numbers%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

            Wiesbaden

            Image
            Wappen Deutschlandkarte 50.0825 8.24 117 Koordinaten: 50° 5′  N , 8° 14′  O Basisdaten Bundesland: Hessen Regierungsbezirk: Darmstadt Höhe: 117 m ü. NHN Fläche: 203,93 km 2 Einwohner: 278.654 (31. Dez. 2017) [1] Bevölkerungsdichte: 1366 Einwohner je km 2 Postleitzahlen: 65183–65207, 55246, 55252 Vorlage:Infobox Gemeinde in Deutschland/Wartung/PLZ enthält Text Vorwahlen: 0611, 06122, 06127, 06134 Kfz-Kennzeichen: WI Gemeindeschlüssel: 06 4 14 000 LOCODE: DE WIB NUTS: DE714 Stadtgliederung: 26 Ortsbezirke Adresse der Stadtverwaltung: Schlossplatz 6 65183 Wiesbaden Webpräsenz: www.wiesbaden.de Oberbürgermeister: Sven Gerich (SPD) Lage der Landeshauptstadt Wiesbaden in Hessen und im Regierungsbezirk Darmstadt Offizielles Logo der Landeshauptstadt Wiesbaden Flagge der Landeshauptstadt Wiesbaden Wiesbaden is
            Read more

            Marschland

            Image
            Kilometerweite Marsch in den Vier- und Marschlanden am Elbdeich Die Wedeler Marschlandschaft in Schleswig-Holstein Der Hadelner Kanal zur Entwässerung der Marsch Die tief gelegene Marsch und ein Entwässerungskanal Das Schöpfwerk Otterndorf im Land Hadeln zur Entwässerung der Medem verfügte damals bereits über die größte Kreiselpumpe Europas. Das Schöpfwerk in Neuhaus für die Aue und des Neuhaus-Bülkauer Kanals Als Marsch(land) (v. niederdt., altsächs. mersc ) – auch Masch , Mersch oder Schwemmland genannt – bezeichnet man eine nacheiszeitlich entstandene geomorphologische Landform im Gebiet der nordwestdeutschen Küsten und Flüsse sowie vergleichbare Landformen weltweit. Inhaltsverzeichnis 1 Landschaft 2 Entstehung 3 Marschböden 4 Nutzung 5 Marschgebiete in Deutschland 6 Siehe auch 7 Literatur 8 Weblinks 9 Einzelnachweise Landschaft | Marschen sind generell flache Landstriche ohne natürliche Erhebungen. Si
            Read more

            Dieringhausen

            Image
            Dieringhausen Stadt Gummersbach 50.982777777778 7.5316666666667 165 Koordinaten: 50° 58′ 58″  N , 7° 31′ 54″  O Höhe: 165  (160–245)  m Einwohner: 5055  (30. Jun. 2016) Postleitzahl: 51645 Vorwahl: 02261 Lage von Dieringhausen in Gummersbach Im Hohl ca. 1927–1930 Ansicht von Südwesten bei Bünghausen Dieringhausen (im örtlichen Dialekt Dierkesen ) ist ein Ortsteil von Gummersbach im Oberbergischen Kreis, Regierungsbezirk Köln, Nordrhein-Westfalen (Deutschland). Inhaltsverzeichnis 1 Geographie 2 Geschichte 3 Kultur 3.1 Sehenswürdigkeiten 3.2 Regelmäßige Veranstaltungen 4 Infrastruktur und Wirtschaft 4.1 Verkehr 4.1.1 Schienen- und Busverkehr 4.1.2 Straßen 4.2 Öffentliche Einrichtungen 4.2.1 Schulen und Bildungseinrichtungen 4.2.2 Kirchliche Einrichtungen 5 Persönlichkeiten 5.1 In Dieringhausen geboren 5.2 In Dieringhausen gelebt 6 Einzelnachweise 7
            Read more