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I do not understand this vector identity proof

  1. Oct 17, 2011 #1
    So I am trying to follow my professors notes. Here is my work on the proof. And on the bottom is my answer and his answer. I know my answer is wrong, as I do not fully understand how to convert the summations at the end to their vector quantities. Is my work incorrect?

    [PLAIN]http://img256.imageshack.us/img256/6175/questionn.gif [Broken]

    I do not even know what F times nabla means. I know nabla times F is divergence. Are they the same????

    EDIT: Oh and his G is my q.

    AND his answer has a -(G*Nabla)*F at the end.
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Oct 23, 2011 #2
    u know, i have done the above proof, i.e,
    curl of (A χ B)
    but it came out to be (B .[itex]\nabla[/itex])A-B([itex]\nabla[/itex] . A)-(A.[itex]\nabla[/itex]) B+ A ([itex]\nabla[/itex] . B)

    u see, i am just a beginner in this topic, and i didn't do it like u did it. instead i broke it down all the way and did it. I know it is stupid but i was not so sure so..... but i did check the answer and it was correct.
     
  4. Oct 23, 2011 #3
    I got my answer to be his answer. My main confusion was linking the formulas to the vector operation in the last step.
     
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