Proving $ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $












4












$begingroup$


I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.



$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$



For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:



$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$



I then simplify further and end up at:



$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$



From here on I don't see any identities, or possible ways to decompose this further.










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
    $endgroup$
    – Chaitanya Tappu
    Nov 30 '18 at 2:29
















4












$begingroup$


I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.



$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$



For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:



$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$



I then simplify further and end up at:



$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$



From here on I don't see any identities, or possible ways to decompose this further.










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
    $endgroup$
    – Chaitanya Tappu
    Nov 30 '18 at 2:29














4












4








4


0



$begingroup$


I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.



$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$



For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:



$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$



I then simplify further and end up at:



$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$



From here on I don't see any identities, or possible ways to decompose this further.










share|cite|improve this question











$endgroup$




I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.



$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$



For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:



$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$



I then simplify further and end up at:



$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$



From here on I don't see any identities, or possible ways to decompose this further.







trigonometry problem-solving






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 30 '18 at 5:06









Blue

48.4k870154




48.4k870154










asked Nov 30 '18 at 2:20









Rawley FowlerRawley Fowler

47116




47116








  • 2




    $begingroup$
    Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
    $endgroup$
    – Chaitanya Tappu
    Nov 30 '18 at 2:29














  • 2




    $begingroup$
    Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
    $endgroup$
    – Chaitanya Tappu
    Nov 30 '18 at 2:29








2




2




$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29




$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29










2 Answers
2






active

oldest

votes


















3












$begingroup$

$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.



$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    you beat me to it. (+1)
    $endgroup$
    – clathratus
    Nov 30 '18 at 2:37



















3












$begingroup$

$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$



$tan x=dfrac1?,sin x=dfrac1?$






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%2f3019535%2fproving-frac-csc-x-cot-x-tan-x-sin-x-cot-x-csc-x%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









    3












    $begingroup$

    $require{cancel}$
    As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.



    $$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
    $$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$






    share|cite|improve this answer











    $endgroup$









    • 1




      $begingroup$
      you beat me to it. (+1)
      $endgroup$
      – clathratus
      Nov 30 '18 at 2:37
















    3












    $begingroup$

    $require{cancel}$
    As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.



    $$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
    $$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$






    share|cite|improve this answer











    $endgroup$









    • 1




      $begingroup$
      you beat me to it. (+1)
      $endgroup$
      – clathratus
      Nov 30 '18 at 2:37














    3












    3








    3





    $begingroup$

    $require{cancel}$
    As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.



    $$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
    $$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$






    share|cite|improve this answer











    $endgroup$



    $require{cancel}$
    As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.



    $$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
    $$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$







    share|cite|improve this answer














    share|cite|improve this answer



    share|cite|improve this answer








    edited Dec 7 '18 at 12:42

























    answered Nov 30 '18 at 2:34









    Robert HowardRobert Howard

    1,9261822




    1,9261822








    • 1




      $begingroup$
      you beat me to it. (+1)
      $endgroup$
      – clathratus
      Nov 30 '18 at 2:37














    • 1




      $begingroup$
      you beat me to it. (+1)
      $endgroup$
      – clathratus
      Nov 30 '18 at 2:37








    1




    1




    $begingroup$
    you beat me to it. (+1)
    $endgroup$
    – clathratus
    Nov 30 '18 at 2:37




    $begingroup$
    you beat me to it. (+1)
    $endgroup$
    – clathratus
    Nov 30 '18 at 2:37











    3












    $begingroup$

    $$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$



    $tan x=dfrac1?,sin x=dfrac1?$






    share|cite|improve this answer









    $endgroup$


















      3












      $begingroup$

      $$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$



      $tan x=dfrac1?,sin x=dfrac1?$






      share|cite|improve this answer









      $endgroup$
















        3












        3








        3





        $begingroup$

        $$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$



        $tan x=dfrac1?,sin x=dfrac1?$






        share|cite|improve this answer









        $endgroup$



        $$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$



        $tan x=dfrac1?,sin x=dfrac1?$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 30 '18 at 3:52









        lab bhattacharjeelab bhattacharjee

        225k15157275




        225k15157275






























            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%2f3019535%2fproving-frac-csc-x-cot-x-tan-x-sin-x-cot-x-csc-x%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

            How to change which sound is reproduced for terminal bell?

            Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents

            Can I use Tabulator js library in my java Spring + Thymeleaf project?