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Homework Help: Tiny question on differential (?) equations.

  1. Mar 1, 2006 #1
    For the potential in an electric field is given:

    http://img402.imageshack.us/img402/4162/naamloos8zn.gif [Broken]

    At x=0 V(x) is at a minimum so:

    dV/dx =0 and d2V/dx2= kQ/(2 sqrt{2} L3)

    Why does it follow that:

    V(x) must be in the form V(x)= V(0) + @ x2 where V(0)= (sqrt{2} kQ)/L and the constant @ = kQ/ (sqrt{2} L 3) ?

    Note that I haven't learnt much yet on solving differential equations.
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Mar 1, 2006 #2
    Doesn't @ need to be kQ/ (4 sqrt {2} L 3)
  4. Mar 1, 2006 #3


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    Staff Emeritus
    Science Advisor

    Think about V(-x), i.e. is V(x) and odd or even function?
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