Differential Equations: How to categorize graph and clockwise vs. counter-clockwise from eigenvalues?












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I'm studying for my Final and having a hard time understanding the criteria for category (Sink, Spiral Sink, Center, etc.) and how to tell whether the direction is clockwise (CW) or counter-clockwise (CCW).



If someone could please tell me whether my understanding (typed below) is correct, I would really appreciate it!



Case 1: If $lambda_1,lambda_2>0$ and real, then it is a Source.



Case 2: If $lambda_1,lambda_2>0$ and complex, then it is a Spiral Source.



Subcase 1: If $lambda_{re}>0$, then motion is CW.



Subcase 2: If $lambda_{re}<0$, then motion is CCW.



Case 3: If $lambda_1,lambda_2<0$ and real, then it is a Sink.



Case 4: If $lambda_1,lambda_2<0$ and complex, then it is a Spiral Sink.



Subcase 1: If $lambda_{re}>0$, then motion is CW.



Subcase 2: If $lambda_{re}<0$, then motion is CCW.



Case 5: If $lambda_1=lambda_2=0$, then it is a Center.



Case 6: If $lambda_1>0>lambda_2$, then it is a Saddle.



Thank you in advance to anyone who can help!










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    1












    $begingroup$


    I'm studying for my Final and having a hard time understanding the criteria for category (Sink, Spiral Sink, Center, etc.) and how to tell whether the direction is clockwise (CW) or counter-clockwise (CCW).



    If someone could please tell me whether my understanding (typed below) is correct, I would really appreciate it!



    Case 1: If $lambda_1,lambda_2>0$ and real, then it is a Source.



    Case 2: If $lambda_1,lambda_2>0$ and complex, then it is a Spiral Source.



    Subcase 1: If $lambda_{re}>0$, then motion is CW.



    Subcase 2: If $lambda_{re}<0$, then motion is CCW.



    Case 3: If $lambda_1,lambda_2<0$ and real, then it is a Sink.



    Case 4: If $lambda_1,lambda_2<0$ and complex, then it is a Spiral Sink.



    Subcase 1: If $lambda_{re}>0$, then motion is CW.



    Subcase 2: If $lambda_{re}<0$, then motion is CCW.



    Case 5: If $lambda_1=lambda_2=0$, then it is a Center.



    Case 6: If $lambda_1>0>lambda_2$, then it is a Saddle.



    Thank you in advance to anyone who can help!










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      I'm studying for my Final and having a hard time understanding the criteria for category (Sink, Spiral Sink, Center, etc.) and how to tell whether the direction is clockwise (CW) or counter-clockwise (CCW).



      If someone could please tell me whether my understanding (typed below) is correct, I would really appreciate it!



      Case 1: If $lambda_1,lambda_2>0$ and real, then it is a Source.



      Case 2: If $lambda_1,lambda_2>0$ and complex, then it is a Spiral Source.



      Subcase 1: If $lambda_{re}>0$, then motion is CW.



      Subcase 2: If $lambda_{re}<0$, then motion is CCW.



      Case 3: If $lambda_1,lambda_2<0$ and real, then it is a Sink.



      Case 4: If $lambda_1,lambda_2<0$ and complex, then it is a Spiral Sink.



      Subcase 1: If $lambda_{re}>0$, then motion is CW.



      Subcase 2: If $lambda_{re}<0$, then motion is CCW.



      Case 5: If $lambda_1=lambda_2=0$, then it is a Center.



      Case 6: If $lambda_1>0>lambda_2$, then it is a Saddle.



      Thank you in advance to anyone who can help!










      share|cite|improve this question









      $endgroup$




      I'm studying for my Final and having a hard time understanding the criteria for category (Sink, Spiral Sink, Center, etc.) and how to tell whether the direction is clockwise (CW) or counter-clockwise (CCW).



      If someone could please tell me whether my understanding (typed below) is correct, I would really appreciate it!



      Case 1: If $lambda_1,lambda_2>0$ and real, then it is a Source.



      Case 2: If $lambda_1,lambda_2>0$ and complex, then it is a Spiral Source.



      Subcase 1: If $lambda_{re}>0$, then motion is CW.



      Subcase 2: If $lambda_{re}<0$, then motion is CCW.



      Case 3: If $lambda_1,lambda_2<0$ and real, then it is a Sink.



      Case 4: If $lambda_1,lambda_2<0$ and complex, then it is a Spiral Sink.



      Subcase 1: If $lambda_{re}>0$, then motion is CW.



      Subcase 2: If $lambda_{re}<0$, then motion is CCW.



      Case 5: If $lambda_1=lambda_2=0$, then it is a Center.



      Case 6: If $lambda_1>0>lambda_2$, then it is a Saddle.



      Thank you in advance to anyone who can help!







      ordinary-differential-equations complex-numbers eigenvalues-eigenvectors differential






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      asked Dec 11 '18 at 23:41









      Mathematic314Mathematic314

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