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Math Help - Equation for a line.

  1. #1
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    Equation for a line.

    Hi. I need help finding a vector for an equation for a line. In the question i'm given 2 points which both have the same distance to the Line.

    Points (2,2) and (0,-2)

    I managed to find a point on the line p1,0) by making a vector out of the 2 given points and then dividing it by half, and so on. But i have no idea how to get the vector. Anybody who can help? Thanks a lot. Been stuck here for like the past hour. Thanks again....

    Juan
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  2. #2
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    Try: \left\langle {1, 0} \right\rangle  + t\left\langle {-2,1} \right\rangle
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  3. #3
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    Thanks!

    Thank you. But how did you get that vector? In the answer sheet it says (2,-1) but i guess its the same thing. How did you come up with (-2,1) ?? Thanks again.

    Juan
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  4. #4
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    Well just look at \left\langle {2, - 1} \right\rangle  =  - \left\langle { - 2,1} \right\rangle . That means that those vectors are parallel.
    So we can use either one of them or any multiple of either.

    As to how I found it: I just found a vector which is perpendicular to the given vector.
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  5. #5
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    Thanks again!

    Oh yeah!! How silly i am. (ulv) = 0 makes them perpendicular to each other. Man i've forgotten so much. Thanks a bunch again!

    Juan
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