Laplace transform of $sin(sqrt 3t)$












0












$begingroup$


This is an interesting question for me:




Find the Laplace transform of $mathcal{L} {sin(sqrt 3t)}$.




I know the Laplace transform of $sin(sqrt t) = frac{sqrtpi}{2s^{3/2}}e^{-1/4s}$, but simply multiplying t by 3 really messes things up.



I've looked through the books solution, and they write:
$mathcal{L} (sin(sqrt 3t)) = mathcal{L}(sin2(sqrtfrac{3}{4}t) = sqrt frac{3pi}{4} e^{-3/4s}{s^{3/2}}$. They say they do this by utilising the Laplace property of $mathcal{L}{frac{sin2sqrt {at}}{sqrt {pi a}}} = frac{e^{-a/s}}{s^{3/2}}$, which I don't understand (for example, there's no $sqrt pi a$ in the denominator, so what the heck?).



Can anyone please help explain how this works?










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    This is an interesting question for me:




    Find the Laplace transform of $mathcal{L} {sin(sqrt 3t)}$.




    I know the Laplace transform of $sin(sqrt t) = frac{sqrtpi}{2s^{3/2}}e^{-1/4s}$, but simply multiplying t by 3 really messes things up.



    I've looked through the books solution, and they write:
    $mathcal{L} (sin(sqrt 3t)) = mathcal{L}(sin2(sqrtfrac{3}{4}t) = sqrt frac{3pi}{4} e^{-3/4s}{s^{3/2}}$. They say they do this by utilising the Laplace property of $mathcal{L}{frac{sin2sqrt {at}}{sqrt {pi a}}} = frac{e^{-a/s}}{s^{3/2}}$, which I don't understand (for example, there's no $sqrt pi a$ in the denominator, so what the heck?).



    Can anyone please help explain how this works?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      This is an interesting question for me:




      Find the Laplace transform of $mathcal{L} {sin(sqrt 3t)}$.




      I know the Laplace transform of $sin(sqrt t) = frac{sqrtpi}{2s^{3/2}}e^{-1/4s}$, but simply multiplying t by 3 really messes things up.



      I've looked through the books solution, and they write:
      $mathcal{L} (sin(sqrt 3t)) = mathcal{L}(sin2(sqrtfrac{3}{4}t) = sqrt frac{3pi}{4} e^{-3/4s}{s^{3/2}}$. They say they do this by utilising the Laplace property of $mathcal{L}{frac{sin2sqrt {at}}{sqrt {pi a}}} = frac{e^{-a/s}}{s^{3/2}}$, which I don't understand (for example, there's no $sqrt pi a$ in the denominator, so what the heck?).



      Can anyone please help explain how this works?










      share|cite|improve this question









      $endgroup$




      This is an interesting question for me:




      Find the Laplace transform of $mathcal{L} {sin(sqrt 3t)}$.




      I know the Laplace transform of $sin(sqrt t) = frac{sqrtpi}{2s^{3/2}}e^{-1/4s}$, but simply multiplying t by 3 really messes things up.



      I've looked through the books solution, and they write:
      $mathcal{L} (sin(sqrt 3t)) = mathcal{L}(sin2(sqrtfrac{3}{4}t) = sqrt frac{3pi}{4} e^{-3/4s}{s^{3/2}}$. They say they do this by utilising the Laplace property of $mathcal{L}{frac{sin2sqrt {at}}{sqrt {pi a}}} = frac{e^{-a/s}}{s^{3/2}}$, which I don't understand (for example, there's no $sqrt pi a$ in the denominator, so what the heck?).



      Can anyone please help explain how this works?







      laplace-transform






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 20 at 5:07









      Dr.DoofusDr.Doofus

      12412




      12412






















          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          I've figured it out.



          It's just manipulating the expression, and then multiplying it by $sqrt frac{3pi}{4} $ to negate the denominator in the Laplace transform. Very smart.






          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%2f3080208%2flaplace-transform-of-sin-sqrt-3t%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've figured it out.



            It's just manipulating the expression, and then multiplying it by $sqrt frac{3pi}{4} $ to negate the denominator in the Laplace transform. Very smart.






            share|cite|improve this answer









            $endgroup$


















              0












              $begingroup$

              I've figured it out.



              It's just manipulating the expression, and then multiplying it by $sqrt frac{3pi}{4} $ to negate the denominator in the Laplace transform. Very smart.






              share|cite|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                I've figured it out.



                It's just manipulating the expression, and then multiplying it by $sqrt frac{3pi}{4} $ to negate the denominator in the Laplace transform. Very smart.






                share|cite|improve this answer









                $endgroup$



                I've figured it out.



                It's just manipulating the expression, and then multiplying it by $sqrt frac{3pi}{4} $ to negate the denominator in the Laplace transform. Very smart.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 20 at 5:12









                Dr.DoofusDr.Doofus

                12412




                12412






























                    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%2f3080208%2flaplace-transform-of-sin-sqrt-3t%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

                    android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

                    SQL update select statement

                    'app-layout' is not a known element: how to share Component with different Modules