Integrating $int_{0}^{a}sqrt{{tanh}(a)-{tanh}(x)};dx$












4












$begingroup$



What is the integral



$$int_{0}^{a}sqrt{{tanh}(a)-{tanh}(x)};dx$$




I have tried various substitutions but couldn't get the answer.



The substitution $x = {tanh}^{-1}y$ has simplified into rational function in y but I couldn't proceed further.



I got



$$int_{0}^{tanh(a)}frac{1}{sqrt{tanh(a)-y}}frac{1}{1-y^{2}} ; .$$










share|cite|improve this question











$endgroup$












  • $begingroup$
    How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
    $endgroup$
    – Matteo
    Jan 23 at 16:14










  • $begingroup$
    Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
    $endgroup$
    – xbh
    Jan 23 at 16:29










  • $begingroup$
    Where did you get this integral?
    $endgroup$
    – Frank W.
    Jan 23 at 16:47










  • $begingroup$
    @FrankW. In quantum mechanics while using WKB method
    $endgroup$
    – Aierel
    Jan 23 at 16:48
















4












$begingroup$



What is the integral



$$int_{0}^{a}sqrt{{tanh}(a)-{tanh}(x)};dx$$




I have tried various substitutions but couldn't get the answer.



The substitution $x = {tanh}^{-1}y$ has simplified into rational function in y but I couldn't proceed further.



I got



$$int_{0}^{tanh(a)}frac{1}{sqrt{tanh(a)-y}}frac{1}{1-y^{2}} ; .$$










share|cite|improve this question











$endgroup$












  • $begingroup$
    How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
    $endgroup$
    – Matteo
    Jan 23 at 16:14










  • $begingroup$
    Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
    $endgroup$
    – xbh
    Jan 23 at 16:29










  • $begingroup$
    Where did you get this integral?
    $endgroup$
    – Frank W.
    Jan 23 at 16:47










  • $begingroup$
    @FrankW. In quantum mechanics while using WKB method
    $endgroup$
    – Aierel
    Jan 23 at 16:48














4












4








4


0



$begingroup$



What is the integral



$$int_{0}^{a}sqrt{{tanh}(a)-{tanh}(x)};dx$$




I have tried various substitutions but couldn't get the answer.



The substitution $x = {tanh}^{-1}y$ has simplified into rational function in y but I couldn't proceed further.



I got



$$int_{0}^{tanh(a)}frac{1}{sqrt{tanh(a)-y}}frac{1}{1-y^{2}} ; .$$










share|cite|improve this question











$endgroup$





What is the integral



$$int_{0}^{a}sqrt{{tanh}(a)-{tanh}(x)};dx$$




I have tried various substitutions but couldn't get the answer.



The substitution $x = {tanh}^{-1}y$ has simplified into rational function in y but I couldn't proceed further.



I got



$$int_{0}^{tanh(a)}frac{1}{sqrt{tanh(a)-y}}frac{1}{1-y^{2}} ; .$$







integration definite-integrals indefinite-integrals






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 23 at 20:09









Blue

48.7k870156




48.7k870156










asked Jan 23 at 15:46









AierelAierel

285




285












  • $begingroup$
    How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
    $endgroup$
    – Matteo
    Jan 23 at 16:14










  • $begingroup$
    Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
    $endgroup$
    – xbh
    Jan 23 at 16:29










  • $begingroup$
    Where did you get this integral?
    $endgroup$
    – Frank W.
    Jan 23 at 16:47










  • $begingroup$
    @FrankW. In quantum mechanics while using WKB method
    $endgroup$
    – Aierel
    Jan 23 at 16:48


















  • $begingroup$
    How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
    $endgroup$
    – Matteo
    Jan 23 at 16:14










  • $begingroup$
    Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
    $endgroup$
    – xbh
    Jan 23 at 16:29










  • $begingroup$
    Where did you get this integral?
    $endgroup$
    – Frank W.
    Jan 23 at 16:47










  • $begingroup$
    @FrankW. In quantum mechanics while using WKB method
    $endgroup$
    – Aierel
    Jan 23 at 16:48
















$begingroup$
How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
$endgroup$
– Matteo
Jan 23 at 16:14




$begingroup$
How about trying with a substitution $sqrt{operatorname{tanh}(a) - operatorname{tanh}{x}} = y$, instead? Might it work?
$endgroup$
– Matteo
Jan 23 at 16:14












$begingroup$
Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
$endgroup$
– xbh
Jan 23 at 16:29




$begingroup$
Typing tips: we use {} to indicate groups, {} to indicate a pair of braces. Your code has lots of uncompleted groups, hence the compiler cannot process them.
$endgroup$
– xbh
Jan 23 at 16:29












$begingroup$
Where did you get this integral?
$endgroup$
– Frank W.
Jan 23 at 16:47




$begingroup$
Where did you get this integral?
$endgroup$
– Frank W.
Jan 23 at 16:47












$begingroup$
@FrankW. In quantum mechanics while using WKB method
$endgroup$
– Aierel
Jan 23 at 16:48




$begingroup$
@FrankW. In quantum mechanics while using WKB method
$endgroup$
– Aierel
Jan 23 at 16:48










2 Answers
2






active

oldest

votes


















4












$begingroup$

$$I=int_0^a sqrt{tanh a-tanh x}dxoverset{tanh x=y}=int_0^{tanh a} sqrt{tanh a-y} frac{dy}{1-y^2}$$
Let us denote $tanh a=n$ for now. And our first goal must be to get rid of the square root, thus a substitution of $n-y =t^2$ would fit great.
$$I=int_0^n frac{sqrt{n-y}}{1-y^2}dy=int^0_{sqrt n} frac{t}{1-(n-t^2)^2}(-2t,)dt=int_0^{sqrt n} frac{2t^2}{1-(n-t^2)^2}dt$$
$$=int_0^sqrt n frac{1+n}{1+n-t^2}dt-int_0^sqrt n frac{1-n}{1-n+t^2}dt$$
$$=frac{1+n}{sqrt{1+n}}operatorname{arctanh}left(frac{t}{sqrt{1+n}}right)bigg|_0^sqrt n-frac{1-n}{sqrt{1-n}}arctanleft(frac{t}{sqrt{1-n}}right)bigg|_0^sqrt n$$
$$={sqrt{1+tanh a}}cdot operatorname{arctanh}left(sqrt{frac{{tanh a}}{1+tanh a}}right)-{sqrt{1-tanh a}}cdot arctanleft(sqrt{frac{{tanh a}}{1-tanh a}}right)$$






share|cite|improve this answer











$endgroup$













  • $begingroup$
    This is the same as directly substituting the entire integrand with the new variable, is it not?
    $endgroup$
    – Matteo
    Jan 23 at 20:37










  • $begingroup$
    Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
    $endgroup$
    – Zacky
    Jan 23 at 20:45



















1












$begingroup$

Hint



Check if this approach is useful. The substitution
$$ y = sqrt{tanh(a)-tanh(x)}$$
gives you
$$y^2 = tanh(a)-tanh(x),$$
and, therefore,
begin{eqnarray}
&&2y dy = -(1-tanh^2(x)) dx\
&&2ydy = -left[1-(tanh(a)-y^2)^2right] dx\
&&frac{2y dy}{(y^2-tanh(a))^2-1} = dx.
end{eqnarray}

Then the integral becomes rational, i.e.
begin{eqnarray}mathcal I &=& int sqrt{tanh(a)-tanh(x)}dx= \
&=&2int frac{y^2dy}{{(y^2-tanh(a))^2-1}}=\
&=&2intfrac{y^2dy}{(y^2-tanh(a)-1)(y^2+1-tanh(a))}=\
&=& 2int frac{y^2dy}{(y-sqrt{tanh(a)+1})(y+sqrt{tanh(a)+1})(y^2+1-tanh(a))},
end{eqnarray}

recalling that $-1leq tanh(x) leq 1$. You can proceed from here with partial fractions.






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%2f3084649%2fintegrating-int-0a-sqrt-tanha-tanhx-dx%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









    4












    $begingroup$

    $$I=int_0^a sqrt{tanh a-tanh x}dxoverset{tanh x=y}=int_0^{tanh a} sqrt{tanh a-y} frac{dy}{1-y^2}$$
    Let us denote $tanh a=n$ for now. And our first goal must be to get rid of the square root, thus a substitution of $n-y =t^2$ would fit great.
    $$I=int_0^n frac{sqrt{n-y}}{1-y^2}dy=int^0_{sqrt n} frac{t}{1-(n-t^2)^2}(-2t,)dt=int_0^{sqrt n} frac{2t^2}{1-(n-t^2)^2}dt$$
    $$=int_0^sqrt n frac{1+n}{1+n-t^2}dt-int_0^sqrt n frac{1-n}{1-n+t^2}dt$$
    $$=frac{1+n}{sqrt{1+n}}operatorname{arctanh}left(frac{t}{sqrt{1+n}}right)bigg|_0^sqrt n-frac{1-n}{sqrt{1-n}}arctanleft(frac{t}{sqrt{1-n}}right)bigg|_0^sqrt n$$
    $$={sqrt{1+tanh a}}cdot operatorname{arctanh}left(sqrt{frac{{tanh a}}{1+tanh a}}right)-{sqrt{1-tanh a}}cdot arctanleft(sqrt{frac{{tanh a}}{1-tanh a}}right)$$






    share|cite|improve this answer











    $endgroup$













    • $begingroup$
      This is the same as directly substituting the entire integrand with the new variable, is it not?
      $endgroup$
      – Matteo
      Jan 23 at 20:37










    • $begingroup$
      Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
      $endgroup$
      – Zacky
      Jan 23 at 20:45
















    4












    $begingroup$

    $$I=int_0^a sqrt{tanh a-tanh x}dxoverset{tanh x=y}=int_0^{tanh a} sqrt{tanh a-y} frac{dy}{1-y^2}$$
    Let us denote $tanh a=n$ for now. And our first goal must be to get rid of the square root, thus a substitution of $n-y =t^2$ would fit great.
    $$I=int_0^n frac{sqrt{n-y}}{1-y^2}dy=int^0_{sqrt n} frac{t}{1-(n-t^2)^2}(-2t,)dt=int_0^{sqrt n} frac{2t^2}{1-(n-t^2)^2}dt$$
    $$=int_0^sqrt n frac{1+n}{1+n-t^2}dt-int_0^sqrt n frac{1-n}{1-n+t^2}dt$$
    $$=frac{1+n}{sqrt{1+n}}operatorname{arctanh}left(frac{t}{sqrt{1+n}}right)bigg|_0^sqrt n-frac{1-n}{sqrt{1-n}}arctanleft(frac{t}{sqrt{1-n}}right)bigg|_0^sqrt n$$
    $$={sqrt{1+tanh a}}cdot operatorname{arctanh}left(sqrt{frac{{tanh a}}{1+tanh a}}right)-{sqrt{1-tanh a}}cdot arctanleft(sqrt{frac{{tanh a}}{1-tanh a}}right)$$






    share|cite|improve this answer











    $endgroup$













    • $begingroup$
      This is the same as directly substituting the entire integrand with the new variable, is it not?
      $endgroup$
      – Matteo
      Jan 23 at 20:37










    • $begingroup$
      Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
      $endgroup$
      – Zacky
      Jan 23 at 20:45














    4












    4








    4





    $begingroup$

    $$I=int_0^a sqrt{tanh a-tanh x}dxoverset{tanh x=y}=int_0^{tanh a} sqrt{tanh a-y} frac{dy}{1-y^2}$$
    Let us denote $tanh a=n$ for now. And our first goal must be to get rid of the square root, thus a substitution of $n-y =t^2$ would fit great.
    $$I=int_0^n frac{sqrt{n-y}}{1-y^2}dy=int^0_{sqrt n} frac{t}{1-(n-t^2)^2}(-2t,)dt=int_0^{sqrt n} frac{2t^2}{1-(n-t^2)^2}dt$$
    $$=int_0^sqrt n frac{1+n}{1+n-t^2}dt-int_0^sqrt n frac{1-n}{1-n+t^2}dt$$
    $$=frac{1+n}{sqrt{1+n}}operatorname{arctanh}left(frac{t}{sqrt{1+n}}right)bigg|_0^sqrt n-frac{1-n}{sqrt{1-n}}arctanleft(frac{t}{sqrt{1-n}}right)bigg|_0^sqrt n$$
    $$={sqrt{1+tanh a}}cdot operatorname{arctanh}left(sqrt{frac{{tanh a}}{1+tanh a}}right)-{sqrt{1-tanh a}}cdot arctanleft(sqrt{frac{{tanh a}}{1-tanh a}}right)$$






    share|cite|improve this answer











    $endgroup$



    $$I=int_0^a sqrt{tanh a-tanh x}dxoverset{tanh x=y}=int_0^{tanh a} sqrt{tanh a-y} frac{dy}{1-y^2}$$
    Let us denote $tanh a=n$ for now. And our first goal must be to get rid of the square root, thus a substitution of $n-y =t^2$ would fit great.
    $$I=int_0^n frac{sqrt{n-y}}{1-y^2}dy=int^0_{sqrt n} frac{t}{1-(n-t^2)^2}(-2t,)dt=int_0^{sqrt n} frac{2t^2}{1-(n-t^2)^2}dt$$
    $$=int_0^sqrt n frac{1+n}{1+n-t^2}dt-int_0^sqrt n frac{1-n}{1-n+t^2}dt$$
    $$=frac{1+n}{sqrt{1+n}}operatorname{arctanh}left(frac{t}{sqrt{1+n}}right)bigg|_0^sqrt n-frac{1-n}{sqrt{1-n}}arctanleft(frac{t}{sqrt{1-n}}right)bigg|_0^sqrt n$$
    $$={sqrt{1+tanh a}}cdot operatorname{arctanh}left(sqrt{frac{{tanh a}}{1+tanh a}}right)-{sqrt{1-tanh a}}cdot arctanleft(sqrt{frac{{tanh a}}{1-tanh a}}right)$$







    share|cite|improve this answer














    share|cite|improve this answer



    share|cite|improve this answer








    edited Jan 23 at 20:12

























    answered Jan 23 at 20:06









    ZackyZacky

    7,4301961




    7,4301961












    • $begingroup$
      This is the same as directly substituting the entire integrand with the new variable, is it not?
      $endgroup$
      – Matteo
      Jan 23 at 20:37










    • $begingroup$
      Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
      $endgroup$
      – Zacky
      Jan 23 at 20:45


















    • $begingroup$
      This is the same as directly substituting the entire integrand with the new variable, is it not?
      $endgroup$
      – Matteo
      Jan 23 at 20:37










    • $begingroup$
      Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
      $endgroup$
      – Zacky
      Jan 23 at 20:45
















    $begingroup$
    This is the same as directly substituting the entire integrand with the new variable, is it not?
    $endgroup$
    – Matteo
    Jan 23 at 20:37




    $begingroup$
    This is the same as directly substituting the entire integrand with the new variable, is it not?
    $endgroup$
    – Matteo
    Jan 23 at 20:37












    $begingroup$
    Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
    $endgroup$
    – Zacky
    Jan 23 at 20:45




    $begingroup$
    Pretty much yes, but it leaves a room to get rid of that $tanh a$, also this was OP's approach so I continued.
    $endgroup$
    – Zacky
    Jan 23 at 20:45











    1












    $begingroup$

    Hint



    Check if this approach is useful. The substitution
    $$ y = sqrt{tanh(a)-tanh(x)}$$
    gives you
    $$y^2 = tanh(a)-tanh(x),$$
    and, therefore,
    begin{eqnarray}
    &&2y dy = -(1-tanh^2(x)) dx\
    &&2ydy = -left[1-(tanh(a)-y^2)^2right] dx\
    &&frac{2y dy}{(y^2-tanh(a))^2-1} = dx.
    end{eqnarray}

    Then the integral becomes rational, i.e.
    begin{eqnarray}mathcal I &=& int sqrt{tanh(a)-tanh(x)}dx= \
    &=&2int frac{y^2dy}{{(y^2-tanh(a))^2-1}}=\
    &=&2intfrac{y^2dy}{(y^2-tanh(a)-1)(y^2+1-tanh(a))}=\
    &=& 2int frac{y^2dy}{(y-sqrt{tanh(a)+1})(y+sqrt{tanh(a)+1})(y^2+1-tanh(a))},
    end{eqnarray}

    recalling that $-1leq tanh(x) leq 1$. You can proceed from here with partial fractions.






    share|cite|improve this answer











    $endgroup$


















      1












      $begingroup$

      Hint



      Check if this approach is useful. The substitution
      $$ y = sqrt{tanh(a)-tanh(x)}$$
      gives you
      $$y^2 = tanh(a)-tanh(x),$$
      and, therefore,
      begin{eqnarray}
      &&2y dy = -(1-tanh^2(x)) dx\
      &&2ydy = -left[1-(tanh(a)-y^2)^2right] dx\
      &&frac{2y dy}{(y^2-tanh(a))^2-1} = dx.
      end{eqnarray}

      Then the integral becomes rational, i.e.
      begin{eqnarray}mathcal I &=& int sqrt{tanh(a)-tanh(x)}dx= \
      &=&2int frac{y^2dy}{{(y^2-tanh(a))^2-1}}=\
      &=&2intfrac{y^2dy}{(y^2-tanh(a)-1)(y^2+1-tanh(a))}=\
      &=& 2int frac{y^2dy}{(y-sqrt{tanh(a)+1})(y+sqrt{tanh(a)+1})(y^2+1-tanh(a))},
      end{eqnarray}

      recalling that $-1leq tanh(x) leq 1$. You can proceed from here with partial fractions.






      share|cite|improve this answer











      $endgroup$
















        1












        1








        1





        $begingroup$

        Hint



        Check if this approach is useful. The substitution
        $$ y = sqrt{tanh(a)-tanh(x)}$$
        gives you
        $$y^2 = tanh(a)-tanh(x),$$
        and, therefore,
        begin{eqnarray}
        &&2y dy = -(1-tanh^2(x)) dx\
        &&2ydy = -left[1-(tanh(a)-y^2)^2right] dx\
        &&frac{2y dy}{(y^2-tanh(a))^2-1} = dx.
        end{eqnarray}

        Then the integral becomes rational, i.e.
        begin{eqnarray}mathcal I &=& int sqrt{tanh(a)-tanh(x)}dx= \
        &=&2int frac{y^2dy}{{(y^2-tanh(a))^2-1}}=\
        &=&2intfrac{y^2dy}{(y^2-tanh(a)-1)(y^2+1-tanh(a))}=\
        &=& 2int frac{y^2dy}{(y-sqrt{tanh(a)+1})(y+sqrt{tanh(a)+1})(y^2+1-tanh(a))},
        end{eqnarray}

        recalling that $-1leq tanh(x) leq 1$. You can proceed from here with partial fractions.






        share|cite|improve this answer











        $endgroup$



        Hint



        Check if this approach is useful. The substitution
        $$ y = sqrt{tanh(a)-tanh(x)}$$
        gives you
        $$y^2 = tanh(a)-tanh(x),$$
        and, therefore,
        begin{eqnarray}
        &&2y dy = -(1-tanh^2(x)) dx\
        &&2ydy = -left[1-(tanh(a)-y^2)^2right] dx\
        &&frac{2y dy}{(y^2-tanh(a))^2-1} = dx.
        end{eqnarray}

        Then the integral becomes rational, i.e.
        begin{eqnarray}mathcal I &=& int sqrt{tanh(a)-tanh(x)}dx= \
        &=&2int frac{y^2dy}{{(y^2-tanh(a))^2-1}}=\
        &=&2intfrac{y^2dy}{(y^2-tanh(a)-1)(y^2+1-tanh(a))}=\
        &=& 2int frac{y^2dy}{(y-sqrt{tanh(a)+1})(y+sqrt{tanh(a)+1})(y^2+1-tanh(a))},
        end{eqnarray}

        recalling that $-1leq tanh(x) leq 1$. You can proceed from here with partial fractions.







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Jan 23 at 17:11

























        answered Jan 23 at 16:50









        MatteoMatteo

        848311




        848311






























            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%2f3084649%2fintegrating-int-0a-sqrt-tanha-tanhx-dx%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

            Mario Kart Wii

            What does “Dominus providebit” mean?

            Antonio Litta Visconti Arese