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western50
Jul 11, 2011, 07:38 PM
Give a parametric formula for the line passing through the point {1,4,5} and moving away in the direction of the vector {2,1,1}.

For this problem, I just wonder if there is any difference if the wording of the problem is "Give a parametric formula for the line passing through the point {1,4,5} and moving with the direction of the vector {2,1,1}. "

For the parametric formula of the original problem (the one that is moving away),I think the line would be {1-2 t,4-t,5-t}, is that correct?

Unknown008
Jul 12, 2011, 12:50 AM
I never have thought of it in this way, but I don't think that 'moving away' changes anything in the question, for whether you go in the direction vector specified or in the direction of the negative of that vector still makes you 'move away' from <1, 4, 5>.

And I would personally put my answer in that form:

x = 1 - 2t
y = 4 - t
z = 5 - t

Otherwise, I think that your answer is acceptable :)