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Math Help - How to move point 'p' through a tangent.

  1. #1
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    How to move point 'p' through a tangent.

    If I have point p defined as P(x,y) where :


    Sin(theta) = y/r and Cos(theta) = x/r.


    How can I move point p through a tangent so that 'P' is


    then twice the distance from the origin ?
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  2. #2
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    Re: How to move point 'p' through a tangent.

    What does it mean to move a point through a tangent?
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  3. #3
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    Re: How to move point 'p' through a tangent.

    Quote Originally Posted by Robertthenewt View Post
    If I have point p defined as P(x,y) where :


    Sin(theta) = y/r and Cos(theta) = x/r.


    How can I move point p through a tangent so that 'P' is


    then twice the distance from the origin ?
    if I interpret your post correctly, P is a point (x,y) on a circle of radius r.

    let the line tangent to the circle at point P be \overline{PP'} where the length of segment \overline{PP'} is r\sqrt{3} ...

    the points P , P' and the origin form a 30-60-90 triangle and point P' will be a distance 2r from the origin.
    Last edited by skeeter; August 2nd 2012 at 02:52 PM.
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    Re: How to move point 'p' through a tangent.

    Ah, almost. Except if the triangle was looked at with the top being the origin and below that P and to the right of that P1. what I was hoping to find a solution for is that this triangle could be at any angle on the circle but the point I would be interested in would be a point projected beneath p by a vector length of size n. So, that the origin and P and P2 would then line up. An extrusion along a path might be a better term to use.
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  5. #5
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    Re: How to move point 'p' through a tangent.

    you need to make a sketch ...
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