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Homework Help: Reparametrization to find arc length

  1. Sep 21, 2011 #1
    1. The problem statement, all variables and given/known data

    Reparametrize the curve with respect to arc length measured from the point where t=0 in the direction of increasing t.

    r(t) = [e^(2t)cos(2t)]i+2j+[e^(2t)sin(2t)]k


    2. Relevant equations

    i know that the derivative of the arc length with respect to t = magnitude of the derivative of r(t).

    3. The attempt at a solution

    I found the derivative and found the magnitude, but am basically lost as of there.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 21, 2011 #2

    lanedance

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    Homework Helper

    start by finding the arc length as function of t
     
  4. Sep 22, 2011 #3
    Let s(t) be the arc length, and I'm sure Ur calculus textbook will have the formula of arc length..
     
  5. Sep 22, 2011 #4
    In fact you can easily "derive" the formula with pythagorus theorem and riemman sum in mind.
     
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