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Homework Help: Would this have been marked correct?

  1. Feb 25, 2010 #1
    I had to expand the brackets in this expression:

    My answer is:
    2df + 2f2 -2de - 2e2

    The answer in my book is the same but all the components are in different places:
    -2e2 +2f2 -2de + 2df

    Would my answer have been ok in an exam?
  2. jcsd
  3. Feb 25, 2010 #2


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    Homework Helper

    Yes, definitely!

    If you would have had any marks deducted, your teacher has issues.
  4. Feb 25, 2010 #3


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    Staff: Mentor

  5. Feb 25, 2010 #4
    Mentallic is right but it doesn't follow in every case but looking at your standard (may be class II) it is always right for you. In higher classes you will find something different. Like in vector multiplication A x B is not equal to B x A. similarly you'll find that A + B is not equal to B + A. But don't worry about it today.
  6. Feb 25, 2010 #5
    Thanks a lot folks!
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