Abstract

Except in trivial cases, an unknown angle is always extracted from a knowledge of its sine and cosine. These two numbers determine the angle unambiguously; and yet no universally accepted notation expresses that angle as a function of those numbers in a single statement. Some authors use “atan2” for this purpose. I argue that this name is not appropriate, and its description as a “four‐quadrant inverse tangent” is misleading. I propose two interchangeable names “” as candidates for the sought‐after function.