Determine the normalised eigenfunctions for the BVP: $y''+λy=0, y(0)=0, y(1)=0$












0












$begingroup$


Solving it I get:
$y(x)=c_1 cos(x sqrt{lambda}) + c_2 sin (x sqrt{lambda})$



$y(0)= C1 + 0 = 0, C1=0$



$y(1)=0+C2sin(sqrt{lambda})=0$



So, $(sqrt{lambda})=npi$, $({lambda})=(npi)^2$



So, $ψ_n= sin(nxpi)$



However, the solution shows that the answer is:



$ψ_n=(sqrt{2})sin(nxpi)$



Where have I gone wrong in this?










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$endgroup$

















    0












    $begingroup$


    Solving it I get:
    $y(x)=c_1 cos(x sqrt{lambda}) + c_2 sin (x sqrt{lambda})$



    $y(0)= C1 + 0 = 0, C1=0$



    $y(1)=0+C2sin(sqrt{lambda})=0$



    So, $(sqrt{lambda})=npi$, $({lambda})=(npi)^2$



    So, $ψ_n= sin(nxpi)$



    However, the solution shows that the answer is:



    $ψ_n=(sqrt{2})sin(nxpi)$



    Where have I gone wrong in this?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Solving it I get:
      $y(x)=c_1 cos(x sqrt{lambda}) + c_2 sin (x sqrt{lambda})$



      $y(0)= C1 + 0 = 0, C1=0$



      $y(1)=0+C2sin(sqrt{lambda})=0$



      So, $(sqrt{lambda})=npi$, $({lambda})=(npi)^2$



      So, $ψ_n= sin(nxpi)$



      However, the solution shows that the answer is:



      $ψ_n=(sqrt{2})sin(nxpi)$



      Where have I gone wrong in this?










      share|cite|improve this question











      $endgroup$




      Solving it I get:
      $y(x)=c_1 cos(x sqrt{lambda}) + c_2 sin (x sqrt{lambda})$



      $y(0)= C1 + 0 = 0, C1=0$



      $y(1)=0+C2sin(sqrt{lambda})=0$



      So, $(sqrt{lambda})=npi$, $({lambda})=(npi)^2$



      So, $ψ_n= sin(nxpi)$



      However, the solution shows that the answer is:



      $ψ_n=(sqrt{2})sin(nxpi)$



      Where have I gone wrong in this?







      fourier-series eigenfunctions sturm-liouville






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      share|cite|improve this question













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      edited Dec 23 '18 at 11:28









      Bernard

      124k741118




      124k741118










      asked Dec 23 '18 at 11:24









      luffyluffy

      92




      92






















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          $begingroup$

          The solution is $C_2sin (npi x).$ It is normalized when $$1=int_{0}^{1} (C_2 sin(npi x))^2 dx=frac{(C_2)^2}{2}.$$ From this follows $C_2=sqrt 2.$






          share|cite|improve this answer









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            $begingroup$

            The solution is $C_2sin (npi x).$ It is normalized when $$1=int_{0}^{1} (C_2 sin(npi x))^2 dx=frac{(C_2)^2}{2}.$$ From this follows $C_2=sqrt 2.$






            share|cite|improve this answer









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              1












              $begingroup$

              The solution is $C_2sin (npi x).$ It is normalized when $$1=int_{0}^{1} (C_2 sin(npi x))^2 dx=frac{(C_2)^2}{2}.$$ From this follows $C_2=sqrt 2.$






              share|cite|improve this answer









              $endgroup$
















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                1





                $begingroup$

                The solution is $C_2sin (npi x).$ It is normalized when $$1=int_{0}^{1} (C_2 sin(npi x))^2 dx=frac{(C_2)^2}{2}.$$ From this follows $C_2=sqrt 2.$






                share|cite|improve this answer









                $endgroup$



                The solution is $C_2sin (npi x).$ It is normalized when $$1=int_{0}^{1} (C_2 sin(npi x))^2 dx=frac{(C_2)^2}{2}.$$ From this follows $C_2=sqrt 2.$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 23 '18 at 13:08









                user376343user376343

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