Inverse Laplace of $frac{s}{s^2+4s+5}$












0












$begingroup$


Find the inverse Laplace Transformation of $frac{s}{s^2+4s+5}$



I obtained...



$$frac{s}{s^2+4s+4-4+5}$$



$$frac{s}{s^2+4s+1}$$



$$frac{s}{(s+2)^2+1}$$



I am not sure what my next step is?










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    Find the inverse Laplace Transformation of $frac{s}{s^2+4s+5}$



    I obtained...



    $$frac{s}{s^2+4s+4-4+5}$$



    $$frac{s}{s^2+4s+1}$$



    $$frac{s}{(s+2)^2+1}$$



    I am not sure what my next step is?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Find the inverse Laplace Transformation of $frac{s}{s^2+4s+5}$



      I obtained...



      $$frac{s}{s^2+4s+4-4+5}$$



      $$frac{s}{s^2+4s+1}$$



      $$frac{s}{(s+2)^2+1}$$



      I am not sure what my next step is?










      share|cite|improve this question











      $endgroup$




      Find the inverse Laplace Transformation of $frac{s}{s^2+4s+5}$



      I obtained...



      $$frac{s}{s^2+4s+4-4+5}$$



      $$frac{s}{s^2+4s+1}$$



      $$frac{s}{(s+2)^2+1}$$



      I am not sure what my next step is?







      ordinary-differential-equations






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 7 '18 at 5:50









      Eevee Trainer

      5,7961936




      5,7961936










      asked Dec 7 '18 at 5:48









      sumthatup11sumthatup11

      11




      11






















          1 Answer
          1






          active

          oldest

          votes


















          5












          $begingroup$

          $$dfrac s{(s+2)^2+1^2}=dfrac{s+2}{(s+2)^2+1^2}-2cdotdfrac1{(s+2)^2+1^2}$$



          Now use $$Lleft(e^{at}cos btright)=dfrac{s-a}{(s-a)^2+b^2}$$



          $$Lleft(e^{at}sin btright)=dfrac b{(s-a)^2+b^2}$$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            See mathworld.wolfram.com/LaplaceTransform.html
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 5:52










          • $begingroup$
            How did you get s = s+2 -2? Why did you add 2?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:00










          • $begingroup$
            @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 6:02












          • $begingroup$
            I do not understand your step in the numerator. I do not understand how s = s+2....?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:06











          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%2f3029524%2finverse-laplace-of-fracss24s5%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









          5












          $begingroup$

          $$dfrac s{(s+2)^2+1^2}=dfrac{s+2}{(s+2)^2+1^2}-2cdotdfrac1{(s+2)^2+1^2}$$



          Now use $$Lleft(e^{at}cos btright)=dfrac{s-a}{(s-a)^2+b^2}$$



          $$Lleft(e^{at}sin btright)=dfrac b{(s-a)^2+b^2}$$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            See mathworld.wolfram.com/LaplaceTransform.html
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 5:52










          • $begingroup$
            How did you get s = s+2 -2? Why did you add 2?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:00










          • $begingroup$
            @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 6:02












          • $begingroup$
            I do not understand your step in the numerator. I do not understand how s = s+2....?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:06
















          5












          $begingroup$

          $$dfrac s{(s+2)^2+1^2}=dfrac{s+2}{(s+2)^2+1^2}-2cdotdfrac1{(s+2)^2+1^2}$$



          Now use $$Lleft(e^{at}cos btright)=dfrac{s-a}{(s-a)^2+b^2}$$



          $$Lleft(e^{at}sin btright)=dfrac b{(s-a)^2+b^2}$$






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            See mathworld.wolfram.com/LaplaceTransform.html
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 5:52










          • $begingroup$
            How did you get s = s+2 -2? Why did you add 2?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:00










          • $begingroup$
            @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 6:02












          • $begingroup$
            I do not understand your step in the numerator. I do not understand how s = s+2....?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:06














          5












          5








          5





          $begingroup$

          $$dfrac s{(s+2)^2+1^2}=dfrac{s+2}{(s+2)^2+1^2}-2cdotdfrac1{(s+2)^2+1^2}$$



          Now use $$Lleft(e^{at}cos btright)=dfrac{s-a}{(s-a)^2+b^2}$$



          $$Lleft(e^{at}sin btright)=dfrac b{(s-a)^2+b^2}$$






          share|cite|improve this answer









          $endgroup$



          $$dfrac s{(s+2)^2+1^2}=dfrac{s+2}{(s+2)^2+1^2}-2cdotdfrac1{(s+2)^2+1^2}$$



          Now use $$Lleft(e^{at}cos btright)=dfrac{s-a}{(s-a)^2+b^2}$$



          $$Lleft(e^{at}sin btright)=dfrac b{(s-a)^2+b^2}$$







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Dec 7 '18 at 5:51









          lab bhattacharjeelab bhattacharjee

          225k15157275




          225k15157275












          • $begingroup$
            See mathworld.wolfram.com/LaplaceTransform.html
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 5:52










          • $begingroup$
            How did you get s = s+2 -2? Why did you add 2?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:00










          • $begingroup$
            @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 6:02












          • $begingroup$
            I do not understand your step in the numerator. I do not understand how s = s+2....?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:06


















          • $begingroup$
            See mathworld.wolfram.com/LaplaceTransform.html
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 5:52










          • $begingroup$
            How did you get s = s+2 -2? Why did you add 2?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:00










          • $begingroup$
            @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
            $endgroup$
            – lab bhattacharjee
            Dec 7 '18 at 6:02












          • $begingroup$
            I do not understand your step in the numerator. I do not understand how s = s+2....?
            $endgroup$
            – sumthatup11
            Dec 7 '18 at 6:06
















          $begingroup$
          See mathworld.wolfram.com/LaplaceTransform.html
          $endgroup$
          – lab bhattacharjee
          Dec 7 '18 at 5:52




          $begingroup$
          See mathworld.wolfram.com/LaplaceTransform.html
          $endgroup$
          – lab bhattacharjee
          Dec 7 '18 at 5:52












          $begingroup$
          How did you get s = s+2 -2? Why did you add 2?
          $endgroup$
          – sumthatup11
          Dec 7 '18 at 6:00




          $begingroup$
          How did you get s = s+2 -2? Why did you add 2?
          $endgroup$
          – sumthatup11
          Dec 7 '18 at 6:00












          $begingroup$
          @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
          $endgroup$
          – lab bhattacharjee
          Dec 7 '18 at 6:02






          $begingroup$
          @sumthatup11, To utilize the two formulas, write $$s=A(s+2)+Bcdot(1)=s(A)+(A+B)implies A=1, 2A+B=0iff B=?$$
          $endgroup$
          – lab bhattacharjee
          Dec 7 '18 at 6:02














          $begingroup$
          I do not understand your step in the numerator. I do not understand how s = s+2....?
          $endgroup$
          – sumthatup11
          Dec 7 '18 at 6:06




          $begingroup$
          I do not understand your step in the numerator. I do not understand how s = s+2....?
          $endgroup$
          – sumthatup11
          Dec 7 '18 at 6:06


















          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%2f3029524%2finverse-laplace-of-fracss24s5%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

          Ellipse (mathématiques)

          Quarter-circle Tiles

          Mont Emei