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Homework Help: Vector Addition using coordinates

  1. Oct 5, 2008 #1
    1. The problem statement, all variables and given/known data
    You have a vector, labelled A, with the coordinates (2,1,1). Subtract vector B, coordinates (3,-1,4) from vector A.

    2. Relevant equations
    Take vector A, and flip vector B in the opposite direction. Line up vector B's tip to vector A's tail, and draw the new vector from tail to tip.

    What I am unsure about are those 3 coordinates. I have only learned in class to use two coordinates. What does the third one mean?

    3. The attempt at a solution
    I'm guessing that one number is the x-component, and that one is the y-component. I have no idea what the third one would be, however. Also, I have no idea what order they are in!!
  2. jcsd
  3. Oct 6, 2008 #2


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    Staff Emeritus
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    The third number is the z-component. They are always written in the order (x, y, z). In this context they are called the components of the vector. To add vectors given their components, just add x-components, to give the resultant vector x-component, the y-components to give the resultant vector y-component.... etc.
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