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Homework Help: Calculating impedance for parallel circuit

  1. Nov 14, 2009 #1
    Hi there,

    Below shows the solution to the circuit.
    However i am confused about how to solve the eq in red box.

    http://img208.imageshack.us/img208/2797/123vv.jpg [Broken]

    do i need to solve it by calculator or more work needs to be done?

    If it's by calculator i am using sharp and i couldnt get the correct answer.

    Please advice. Thanks.

    Attached Files:

    • 123.JPG
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    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 14, 2009 #2


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    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi spiderabbit! Welcome to PF! :smile:

    The trick for putting (a + ib)/(p + iq) into standard form is to myltiply both top and bootm by the complex conjugate of the bottom …

    (a + ib)/(p + iq) = (a + ib)(p - iq)/(p2 + q2) :wink:

    That does give your answer of 4 + j8 … what is worrying you?
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