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Math Help - cross product question of j ,k ..

  1. #1
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    cross product question of j ,k ..

    http://i26.tinypic.com/27zdaiv.gif

    i know that i should do right hand rule to know the result
    but here the vectors are weird

    ??
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  2. #2
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    Quote Originally Posted by transgalactic View Post
    http://i26.tinypic.com/27zdaiv.gif

    i know that i should do right hand rule to know the result
    but here the vectors are weird

    ??
    Use this general formula:
    (a\vec{i}+ b\vec{j}+ c\vec{k})\times(u\vec{i}+ v\vec{j}+ w\vec{k})<br />
= (bw- cv)\vec{i}+ (cu- aw)\vec{j}+ (av- bu)\vec{k}
    which can be remembered more easily by thinking of it as a "determinant":
    = \left|\begin{array}{ccc}\vec{i} & \vec{j} & \vec{k} \\ a & b & c \\ u & v & w\end{array}\right|
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