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Homework Help: Complex Number

  1. Sep 14, 2006 #1
    Calculate the real part, the imaginary part, and the absolute value of the following expression:

    i * [(1+2i)(5-3i)+3i/(1+i)].

    So I did the math out this way:

    (1+2i)(5-3i)= 11+7i
    (11+7i)+3i/(1+i)= (4+21i)/(1+i)
    i * [(4+21i)/(1+i)] = (4i-21)/(1+i)

    Is this correct and what do you call the imaginary part and the real part if a denominator exists with an imaginary i?

    Thanks for any help.
  2. jcsd
  3. Sep 14, 2006 #2
    Yeah I figured it out. You just multiply it by its conjugate earlier in the process.
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