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Vector algebra

  1. Sep 27, 2006 #1

    Okay so i need a little help.

    Heres the problem.

    The question asks...

    Find a vector that has the same direction as <-2,4,2> but has length 6.

    So i Did the |v|= Sqrt( A1^2+A2^2+A3^2)= sqrt(24) which is how you begin to find the unit vector with the same direction. I get stumped on how to find it with length 6. The new vector with the same direction would be... <-2/Sqrt(24), 4/Sqrt(24), 2/Sqrt(24)... but.. what about the length of 6..?

    Can anybody help me? What do i do with this length of 6?

    ... any help would be awesome!!!!!
  2. jcsd
  3. Sep 27, 2006 #2
    You simply multiply your last vector by six. Because your last vector has the length of one, you would get a vector of length six just by simply multiplying your vector by 6. That's the whole point of unit vectors. They make calculations really easy. :biggrin:
  4. Sep 27, 2006 #3


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    Homework Helper

    Why the same post two times?
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