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Homework Help: Simple Derivative Question

  1. Oct 20, 2008 #1
    1. The problem statement, all variables and given/known data
    Suppose the x coordinate of a pie is given as a function of time t by
    x(t) = (u^2)(t^2) + 3ut,
    where u is independent of t. Calculate (dx/dt) and (dx/du). Also, whihc one of the above derivatives (if either) give you vx, the x component of the pie's velocity?

    2. Relevant equations
    Just derivative rules.

    3. The attempt at a solution

    (dx/dt)= 2(u^2)t + 3u

    (dx/du)=2u(t^2) + 3t

    Since t represents tiem in this function, to obtain the velocity you must use (dx/dt).

    Please let me know if this is correct or if I am missing a step.
  2. jcsd
  3. Oct 20, 2008 #2
    I don't understand why my problem has not been answered yet while others after me have . . I have given you all the required information. Please let me know anything else you may need. Thanks.
  4. Oct 20, 2008 #3


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    Science Advisor

    No particular reason why one question will be answered and another will not. You cannot, in general, expect a question to be answer in a few minutes or even a few hours. People don't sit around waiting for questions!

    It looks to me like you answers are correct.
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