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Total charge in a circuit

  1. Mar 11, 2008 #1
    1. The problem statement, all variables and given/known data
    The total charge that has entered a circuit element is q(t)=2(3 − e[tex]^{-4t}[/tex]) when t≥0 and
    q(t)=0 when t<0. Determine the current in this circuit element for t≥0.


    2. Relevant equations
    Differentiation


    3. The attempt at a solution

    i(t) = 2(4e[tex]^{-4t}[/tex]) + 3 - e[tex]^{-4t}[/tex]

    i(t) = 7e[tex]^{-4t}[/tex] + 3

    However the answer says 8e[tex]^{-4t}[/tex]

    What have I done wrong?
     
  2. jcsd
  3. Mar 11, 2008 #2
    Nvm. Dumb mistake, just realized. Solved.
     
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