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Homework Help: Finding the absolute value (modulus) and solving equation please help

  1. Jul 2, 2011 #1
    1. | (2-i)(3+2i)(-5-6i)(-7+3i) / (-4+i) |



    2. Relevant equations



    3. Im pretty sure im not computing it right but this is what i come up with.

    square root of 5* square root of 13* square root of 61* square root of 58 / square root of 17.
     
  2. jcsd
  3. Jul 2, 2011 #2

    Dick

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    I'm really sure you are computing it right. |a*b|=|a|*|b|, yes? Why do you think it's not right?
     
  4. Jul 2, 2011 #3
    I'm not sure if the value of i by itself is 1 or whether or not to include it when I am finding the square root.
     
  5. Jul 2, 2011 #4

    Dick

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    The absolute value of a+bi where a and b are both real is sqrt(a^2+b^2). It's the length of the hypotenuse of the triangle with real side a and imaginary perpendicular side b in the Argand diagram. It's the pythagorean theorem. |1|=1 and |i|=1. You are doing everything correctly. Trust me.
     
  6. Jul 2, 2011 #5
    Ok, thanks for the help. Making sure but theres nothing more to do to this problem, correct?
     
  7. Jul 3, 2011 #6

    Dick

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    Not really. You could collect the square roots, or you could write it as an approximate decimal. But I don't see any reason to do that.
     
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