# Express in Polar Coordinate

1. Nov 14, 2004

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. Nov 14, 2004

### tiger_striped_cat

go to:

http://mathworld.wolfram.com/PolarCoordinates.html

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.

3. Nov 15, 2004

### James R

In two dimensions, the transformations are:

$$x = r\cos \theta, \qquad y = r\sin \theta$$

That's all you need.

4. Nov 15, 2004

### tiger_striped_cat

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.