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Homework Help: Express in Polar Coordinate

  1. Nov 14, 2004 #1
    How do I express this in polar coordinates?

    (x-h)^2+(y-k)^2= h^2+k^2

    It is a circle with k and h greater than 0.
  2. jcsd
  3. Nov 14, 2004 #2
    go to:


    I think the transforms would be

    x--> rcos theta
    y--> r sin theta
    h --> R cos theta'
    k --> R sin theta'

    4 prameters to describe the points on a shifted circle (shifted orgin because of the k and h terms) in either cartesian or polar coordinates

    Not sure, but I think.
  4. Nov 15, 2004 #3

    James R

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    In two dimensions, the transformations are:

    [tex]x = r\cos \theta, \qquad y = r\sin \theta[/tex]

    That's all you need.
  5. Nov 15, 2004 #4
    Yeah this makes sense. Sorry for my mistake. You'll only need two variables to plot a 1-d object in a 2d space.

    You would need four parameters to specify a shifted circle in either coordinate system. (The k and h parameters will propagate through your transformation.) You could transform this shift into polar coordinates as well (and you would have to if this was a complicated mechanics problem) but you don't even need to bother with this because it is given as a constant.

    Hope I didn't mess you up. Sorry again.
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