atan21

atan21 is a term that may refer to different concepts depending on the context. It is not an officially standardized mathematical function or a widely recognized object with a single definition.

In mathematics and computing, atan21 is most commonly read as the arctangent of 21, written atan(21). The arctangent of 21 is approximately 1.523 radians, or about 87.3 degrees. This value follows from arctan(21) = π/2 − arctan(1/21).

In programming and software naming, atan21 may be used as an identifier for a function, variable, or configuration option that combines the concept of arctangent with the numeric suffix 21. Such use is informal and language dependent; there is no standard library function named atan21.

In data management, product labeling, or project naming, atan21 can serve as an arbitrary code, model number, or dataset identifier defined by a specific organization.

Because the term has no universal definition, the exact meaning of atan21 should be inferred from the surrounding context. Related mathematical function: arctan; related two-argument form: atan2.