Learning about functions containing derivatives?












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$begingroup$


Ideally, I'm looking to "solve" $$f(x)=x-f'(x-s),quad where,, x ,>=0,quad s=1, quad and quad f(-s) = 0$$
and the moving on to the same format but this equation instead:
$$f(x)=sign(x)-sign(f'(x-s))$$
But I ended up with a ton of questions while attempting to solve it. I'd break it into smaller questions but they seem to my untrained eye to be simple answers about properties on functions of this type.




  1. As far as I can tell this is a chaotic function? So there is no solution correct?

  2. Is this generally true of any function containing the derivative of
    a translated copy? I know it's not generally true if we remove the
    translation.

  3. Is there a name for this "recursive derivative" so I
    can research more about it, or is it just a blanket term of
    differential equation?

  4. I noticed that no matter how I calculated the
    sequence, as long as the spacing was even the generated sequence was
    identical for each term (scaled based on $s$), so f(1) depends on the
    spacing used to get there, not sensitivity to initial conditions, or even accuracy, is there a name for this property, and/or is the $s$ spacing considered
    part of initial conditions?


Assuming I didn't define the function correctly, here's the first few terms:
$$0,1,1,3,2,6,2,11,-1,21,-12,44,-44,101,-131,247$$










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$endgroup$

















    0












    $begingroup$


    Ideally, I'm looking to "solve" $$f(x)=x-f'(x-s),quad where,, x ,>=0,quad s=1, quad and quad f(-s) = 0$$
    and the moving on to the same format but this equation instead:
    $$f(x)=sign(x)-sign(f'(x-s))$$
    But I ended up with a ton of questions while attempting to solve it. I'd break it into smaller questions but they seem to my untrained eye to be simple answers about properties on functions of this type.




    1. As far as I can tell this is a chaotic function? So there is no solution correct?

    2. Is this generally true of any function containing the derivative of
      a translated copy? I know it's not generally true if we remove the
      translation.

    3. Is there a name for this "recursive derivative" so I
      can research more about it, or is it just a blanket term of
      differential equation?

    4. I noticed that no matter how I calculated the
      sequence, as long as the spacing was even the generated sequence was
      identical for each term (scaled based on $s$), so f(1) depends on the
      spacing used to get there, not sensitivity to initial conditions, or even accuracy, is there a name for this property, and/or is the $s$ spacing considered
      part of initial conditions?


    Assuming I didn't define the function correctly, here's the first few terms:
    $$0,1,1,3,2,6,2,11,-1,21,-12,44,-44,101,-131,247$$










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Ideally, I'm looking to "solve" $$f(x)=x-f'(x-s),quad where,, x ,>=0,quad s=1, quad and quad f(-s) = 0$$
      and the moving on to the same format but this equation instead:
      $$f(x)=sign(x)-sign(f'(x-s))$$
      But I ended up with a ton of questions while attempting to solve it. I'd break it into smaller questions but they seem to my untrained eye to be simple answers about properties on functions of this type.




      1. As far as I can tell this is a chaotic function? So there is no solution correct?

      2. Is this generally true of any function containing the derivative of
        a translated copy? I know it's not generally true if we remove the
        translation.

      3. Is there a name for this "recursive derivative" so I
        can research more about it, or is it just a blanket term of
        differential equation?

      4. I noticed that no matter how I calculated the
        sequence, as long as the spacing was even the generated sequence was
        identical for each term (scaled based on $s$), so f(1) depends on the
        spacing used to get there, not sensitivity to initial conditions, or even accuracy, is there a name for this property, and/or is the $s$ spacing considered
        part of initial conditions?


      Assuming I didn't define the function correctly, here's the first few terms:
      $$0,1,1,3,2,6,2,11,-1,21,-12,44,-44,101,-131,247$$










      share|cite|improve this question











      $endgroup$




      Ideally, I'm looking to "solve" $$f(x)=x-f'(x-s),quad where,, x ,>=0,quad s=1, quad and quad f(-s) = 0$$
      and the moving on to the same format but this equation instead:
      $$f(x)=sign(x)-sign(f'(x-s))$$
      But I ended up with a ton of questions while attempting to solve it. I'd break it into smaller questions but they seem to my untrained eye to be simple answers about properties on functions of this type.




      1. As far as I can tell this is a chaotic function? So there is no solution correct?

      2. Is this generally true of any function containing the derivative of
        a translated copy? I know it's not generally true if we remove the
        translation.

      3. Is there a name for this "recursive derivative" so I
        can research more about it, or is it just a blanket term of
        differential equation?

      4. I noticed that no matter how I calculated the
        sequence, as long as the spacing was even the generated sequence was
        identical for each term (scaled based on $s$), so f(1) depends on the
        spacing used to get there, not sensitivity to initial conditions, or even accuracy, is there a name for this property, and/or is the $s$ spacing considered
        part of initial conditions?


      Assuming I didn't define the function correctly, here's the first few terms:
      $$0,1,1,3,2,6,2,11,-1,21,-12,44,-44,101,-131,247$$







      derivatives






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      share|cite|improve this question













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      share|cite|improve this question








      edited Dec 4 '18 at 12:45







      Black

















      asked Dec 4 '18 at 11:24









      BlackBlack

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