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Distance between two points in polar coordinate system.

  1. May 5, 2008 #1

    Any ideas on how to calculate distance between two points in Polar coordinate system without converting their coordinates to Cartesian?

    Ps. I know that if I converted from Polar (r, t) to Cartesian (x, y) by x = r.cos(t), y = r.sin(t), then the distance between two points would be d = sqrt((x1 - x2)^2 + (y1 - y2)^2).

  2. jcsd
  3. May 6, 2008 #2
    You use the law of cosines.
    Construct a triangle with vertices at the origin, and the two points.
    Its a cool trick, but makes for a huge pain in the ass for calculating inverse square laws etc. in polar/spherical.

    I can elaborate if the setup doesn't make sense.
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