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Chain rule

  1. Feb 10, 2014 #1
    Hi fi you look at quesiotn 16b in the following link they try to find dE/dx.

    they use the chain rule. the chain rule says dF/dt=dx/dt*dF/dx+dy/dt*dF/dy if F=f(x,y) and x=f(t) and y=f(t).

    But in 16b they're trying to find dE/dx and as part of the use of the chain rule they try to find dt'/dx (in the first equation under where it says 'a galilean transform...') however t' is not a function of x, so i don't understand why they're taking the derivative of t' wrt to x.

  2. jcsd
  3. Feb 10, 2014 #2


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    That's very simple,
    [tex]\frac{\partial t'}{\partial x}=0.[/tex]
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