Which term refers to the final position of the radius vector?

The term that refers to the final position of the radius vector is "terminal side." In the context of vectors, particularly in polar coordinates or trigonometry, the terminal side is the position where the vector ends or points after being drawn from the origin.

When visualizing a vector originating from a point (usually the origin in a coordinate system), the initial side represents where the vector starts, while the terminal side describes where it concludes. This concept is crucial when discussing angles in standard position, where the angle is measured from the initial side to the terminal side. Understanding this distinction is essential for accurately interpreting geometric and trigonometric concepts.