Find an equation of the tangent line of the exponential function at the point (0,1)












1












$begingroup$


So I differentiated the expression
$$ y=e^{2x}cos(pi x) $$
And I got
$$ y'=2e^{2x}cos(pi x)-pi e^{2x}sin(pi x)$$
But when from the given point $(0,1)$ when I plug in zero I get 2



I looked the answer up in the back of my textbook (which I know I shouldn't do) and the answer is $y=2x+1$










share|cite|improve this question











$endgroup$












  • $begingroup$
    $y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
    $endgroup$
    – Anurag A
    Dec 11 '18 at 2:28












  • $begingroup$
    I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
    $endgroup$
    – T. Bongers
    Dec 11 '18 at 2:30
















1












$begingroup$


So I differentiated the expression
$$ y=e^{2x}cos(pi x) $$
And I got
$$ y'=2e^{2x}cos(pi x)-pi e^{2x}sin(pi x)$$
But when from the given point $(0,1)$ when I plug in zero I get 2



I looked the answer up in the back of my textbook (which I know I shouldn't do) and the answer is $y=2x+1$










share|cite|improve this question











$endgroup$












  • $begingroup$
    $y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
    $endgroup$
    – Anurag A
    Dec 11 '18 at 2:28












  • $begingroup$
    I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
    $endgroup$
    – T. Bongers
    Dec 11 '18 at 2:30














1












1








1





$begingroup$


So I differentiated the expression
$$ y=e^{2x}cos(pi x) $$
And I got
$$ y'=2e^{2x}cos(pi x)-pi e^{2x}sin(pi x)$$
But when from the given point $(0,1)$ when I plug in zero I get 2



I looked the answer up in the back of my textbook (which I know I shouldn't do) and the answer is $y=2x+1$










share|cite|improve this question











$endgroup$




So I differentiated the expression
$$ y=e^{2x}cos(pi x) $$
And I got
$$ y'=2e^{2x}cos(pi x)-pi e^{2x}sin(pi x)$$
But when from the given point $(0,1)$ when I plug in zero I get 2



I looked the answer up in the back of my textbook (which I know I shouldn't do) and the answer is $y=2x+1$







calculus exponential-function






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 11 '18 at 2:33









Dando18

4,68241235




4,68241235










asked Dec 11 '18 at 2:26









Eric BrownEric Brown

757




757












  • $begingroup$
    $y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
    $endgroup$
    – Anurag A
    Dec 11 '18 at 2:28












  • $begingroup$
    I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
    $endgroup$
    – T. Bongers
    Dec 11 '18 at 2:30


















  • $begingroup$
    $y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
    $endgroup$
    – Anurag A
    Dec 11 '18 at 2:28












  • $begingroup$
    I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
    $endgroup$
    – T. Bongers
    Dec 11 '18 at 2:30
















$begingroup$
$y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
$endgroup$
– Anurag A
Dec 11 '18 at 2:28






$begingroup$
$y'(0)=2$ gives you the slope of the line at $(0,1)$. You still need to find the equation of the line (given it's slope and a point lying on it).
$endgroup$
– Anurag A
Dec 11 '18 at 2:28














$begingroup$
I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
$endgroup$
– T. Bongers
Dec 11 '18 at 2:30




$begingroup$
I think this might be a case where you're not sure what you're actually looking for. You say you get $2$, which is indeed $y'(0)$. But you're not looking for a number, you're looking for a line.
$endgroup$
– T. Bongers
Dec 11 '18 at 2:30










1 Answer
1






active

oldest

votes


















0












$begingroup$

You are looking for a line $(y-y_0)=m(x-x_0)$, where $(x_0,y_0)$ is a point on the line and $m$ is the slope of the line.



You are correct in finding the derivative, since $m=y'(0)$. That is, the derivative at $x_0$ is the slope of the tangent line at $x_0$. So now you just have to use the point given to find the equation of the line,



$$ (y-1) = 2(x-0) implies y=2x+1 $$






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%2f3034793%2ffind-an-equation-of-the-tangent-line-of-the-exponential-function-at-the-point-0%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












    $begingroup$

    You are looking for a line $(y-y_0)=m(x-x_0)$, where $(x_0,y_0)$ is a point on the line and $m$ is the slope of the line.



    You are correct in finding the derivative, since $m=y'(0)$. That is, the derivative at $x_0$ is the slope of the tangent line at $x_0$. So now you just have to use the point given to find the equation of the line,



    $$ (y-1) = 2(x-0) implies y=2x+1 $$






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      You are looking for a line $(y-y_0)=m(x-x_0)$, where $(x_0,y_0)$ is a point on the line and $m$ is the slope of the line.



      You are correct in finding the derivative, since $m=y'(0)$. That is, the derivative at $x_0$ is the slope of the tangent line at $x_0$. So now you just have to use the point given to find the equation of the line,



      $$ (y-1) = 2(x-0) implies y=2x+1 $$






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        You are looking for a line $(y-y_0)=m(x-x_0)$, where $(x_0,y_0)$ is a point on the line and $m$ is the slope of the line.



        You are correct in finding the derivative, since $m=y'(0)$. That is, the derivative at $x_0$ is the slope of the tangent line at $x_0$. So now you just have to use the point given to find the equation of the line,



        $$ (y-1) = 2(x-0) implies y=2x+1 $$






        share|cite|improve this answer









        $endgroup$



        You are looking for a line $(y-y_0)=m(x-x_0)$, where $(x_0,y_0)$ is a point on the line and $m$ is the slope of the line.



        You are correct in finding the derivative, since $m=y'(0)$. That is, the derivative at $x_0$ is the slope of the tangent line at $x_0$. So now you just have to use the point given to find the equation of the line,



        $$ (y-1) = 2(x-0) implies y=2x+1 $$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 11 '18 at 2:37









        Dando18Dando18

        4,68241235




        4,68241235






























            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%2f3034793%2ffind-an-equation-of-the-tangent-line-of-the-exponential-function-at-the-point-0%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

            Plaza Victoria

            Puebla de Zaragoza

            Musa