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    This is the question I'm stuck on, I've got part a done but it's mainly part b that I cant do, I just don't really know where to begin. Any help would be appreciated.
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    (Original post by Relentas)
    https://i.gyazo.com/6e4c7e83c8014155...5e2f28eb58.png
    This is the question I'm stuck on, I've got part a done but it's mainly part b that I cant do, I just don't really know where to begin. Any help would be appreciated.
    Just dot the two vectors since its asking for a dot product.

    Take the two vectors, and expand the brackets
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    (Original post by RDKGames)
    Just dot the two vectors since its asking for a dot product.

    Take the two vectors, and expand the brackets
    Surely that just gives 2a^2 + 2b^2

    OM = a + 2b
    OL = 2a + b
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    (Original post by Relentas)
    Surely that just gives 2a^2 + 2b^2

    OM = a + 2b
    OL = 2a + b
    Erm.. no

    (a+2b).(2a+b) = 2a.a + 5a.b + 2b.b

    Then just use the fact that a.a = magnitude(a)^2
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    (Original post by RDKGames)
    Erm.. no

    (a+2b).(2a+b) = 2a.a + 5a.b + 2b.b

    Then just use the fact that a.a = magnitude(a)^2
    Ohh, I was treating a and b as actual units rather than vectors, this helped a lot, thanks!
 
 
 
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