Definition: a method of representing points in a plane by the use of ordered pairs.
The polar coordinate system consists of an origin, the pole, a polar axis and a ray of specific angle.
The polar axis is a line that originates at the origin and extends indefinitely in any given direction.
The position of any point in the plane is determined by its distance from the origin and by the angle that the line makes with the polar axis.
The coordinates of the polar coordinate system are seen above in P.
The angle is positive if it is generated by a counterclockwise rotation of the polar axis, and is negative if it is generated by a clock wise rotation.
The graph of an equation in polar coordinates is a set of all points, each of which has at least one pair of polar coordinates that satisfies the given equation.