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Homework Help: Vectors and Lines - Confirmation

  1. Nov 5, 2005 #1
    Hey,

    I just would like confirmation on this question.
    A parallelogram has sides A,B, BC, CD, DA. Given A(1,-1,2), C(2,1,0) and the midpoint M(1,0,-3) of AB, find BD(vector).

    This is what I did. To find point B, I used the midpoint formula

    (1,0,-3) = 1/2[(x+1), (-1+y), (2+z)]

    Solving that, I got B as (1,1,-8)

    I then found AB = (1,1,-8) - (1,-1,2) = (0,2,-10)

    I then found D by saying (2,1,0) - (0,2,-10) = (2,-1,10)

    Finally BD = (2,-1,10) - (1,1,-8) = (1,-2,18)

    Im not sure if I did this correctly of even if my method at all was correct. Any confirmation would be much apprecieated.
     
  2. jcsd
  3. Nov 6, 2005 #2
    looks good to me
     
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