Why Is the Polar Form of the Position Vector Defined as r = r\vec{r}?

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The polar form of the position vector is defined as r = r\vec{r} to represent a point in two-dimensional space using polar coordinates, where r is the radial distance from the origin and θ is the angle. While it may seem that two parameters are needed to define a position, the polar form effectively combines these into a single expression by using the unit vector \vec{r} to indicate direction. The magnitude r indeed represents the length of the vector \vec{r}, while the angle θ provides the necessary orientation. This formulation simplifies the representation of points in polar coordinates, making it easier to work with in various mathematical contexts. Understanding this relationship is crucial for applications in physics and engineering.
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If we have a position vector \vec{r} = x\vec{i} + y\vec{j} why is the polar form of the equation r = r\vec{r}? Don't we need two parameters to define a postition? And r is the magnitude of \vec{r}?

Thanks
 
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sherlockjones said:
If we have a position vector \vec{r} = x\vec{i} + y\vec{j} why is the polar form of the equation r = r\vec{r}? Don't we need two parameters to define a postition? And r is the magnitude of \vec{r}?

Thanks
The two parameters are r and \theta.

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