CK-12-Pre-Calculus Concepts

10.1. Polar and Rectangular Coordinates http://www.ck12.org

10.1 Polar and Rectangular Coordinates

In the rectangular coordinate system, points are identified by their distances from thexandyaxes. In thepolar
coordinate system,points are identified by their angle on the unit circle and their distance from the origin. You
can use basic right triangle trigonometry to translate back and forth between the two representations of the same
point. How are lines and other functions affected by this new coordinate system?

Watch This

MEDIA

Click image to the left for use the URL below.

URL: http://www.ck12.org/flx/render/embeddedobject/62008

http://www.youtube.com/watch?v=-tZR3ggdoIU James Sousa: Polar Coordinates

Guidance

Rectangular coordinates are the ordinary(x,y)coordinates that you are used to.

Polar coordinates represent the same point, but describe the point by its distance from the origin(r)and its angle on
the unit circle(θ). To translate back and forth between polar and rectangular coordinates you should use the basic
trig relationships:

sinθ=yr→r·sinθ=y

cosθ=xr→r·cosθ=x