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Homework Help: Finding a vector with given properties

  1. Dec 11, 2011 #1
    So I need to find a vector v with these properties
    1. magnitude of 10
    2. angle of 45° with positive x-axis
    3. angle of 75° with positive y-axis
    4. positive k component.

    I understand basically just that the k component has to be positive.
    Any help would be appreciated.
  2. jcsd
  3. Dec 11, 2011 #2


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    Use the following scalar products (dot products).

    [itex]\vec{v}\cdot \hat{i}[/itex]

    [itex]\vec{v}\cdot \hat{j}[/itex]

    In general, [itex]\vec{A}\cdot\vec{B}=\left|\vec{A}\right|\left|\vec{B}\right|\cos(\theta)[/itex]
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