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    find an equation in the form r.n =p which contains the line l and the point with position vector a where

    l : r =-2i +3j -k + t (2i -j -3k ), a =-3i +j 2k


    ne1 help me on dis plz?
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    r = (-2,3,-1) + t(2,3,-1)
    the point (-2,3,-1) is on the line (at t=0), so a line from that point to a = (-3,1,2) is:

    (-3,1,2)-(-2,3,1) = (-1,-2,1)

    n is the vector perpendicular to both (-1,-2,1) and (2,3,-1)
    => n = (-1,-2,1) x (2,3,-1) = (-1,1,1)

    p = (-2,3,-1) . (-1,1,1) = 4

    => r.(-i+j+k) = 4
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    no un4tun8ly this isnt the right answer

    the answer is something like r.(9i+3j+5k) = -14 or something like that
    the 9 and 14 are definitly right
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    I found the mistake (highlighted!). Just a minus sign. shows you how easy it is to make mistakes ( :eek: )

    r = (-2,3,-1) + t(2,3,-1)
    the point (-2,3,-1) is on the line (at t=0), so a line from that point to a = (-3,1,2) is:

    (-3,1,2)-(-2,3,-1) = (-1,-2,3)

    n is the vector perpendicular to both (-1,-2,3) and (2,3,-1)
    => n = (-1,-2,3) x (2,3,-1) = (-7,5,1)

    p = (-2,3,-1) . (-7,5,1) = 28

    => r.(-7i+5j+k) = 28
 
 
 

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