Final answer:
In a plane, two coordinates are required to identify a system. The Cartesian coordinate system uses (x, y) coordinates, while the polar coordinate system uses a radial and angular coordinate.
Step-by-step explanation:
In a plane, there are two equivalent coordinate systems: the Cartesian coordinate system and the polar coordinate system.
In the Cartesian coordinate system, we need two coordinates, usually represented as (x, y), to identify a point in the plane. The x-coordinate tells us the position of the point along the x-axis, and the y-coordinate tells us the position along the y-axis.
In the polar coordinate system, we need two coordinates as well. The first coordinate, called the radial coordinate, gives the distance from the origin to the point. The second coordinate, called the angular coordinate, gives the direction from the origin to the point.