fxyz

Fxyz is a label used in diverse technical contexts to denote a quantity, function, or object that depends on three variables x, y, and z, or the three Cartesian components of a vector. The ambiguity of the term means its precise meaning is defined by context.

In mathematics, Fxyz commonly stands for a three-variable function F(x,y,z). It is used in definitions, examples, and proofs to illustrate properties such as partial derivatives, level surfaces, or optimization in three dimensions. In computing and software templates, Fxyz is often used as a placeholder function name in sample code that accepts three inputs and returns a value.

In physics and engineering, components of a vector are often written as F_x, F_y, F_z. When discussed collectively, the set {F_x, F_y, F_z} may be described informally as Fxyz, though this is not standard mathematical notation. The term may appear in didactic or shorthand expressions rather than formal equations.

In biology and other fields, uppercase variants like FXYZ appear in gene or protein nomenclature in some databases, but their meanings are specific to particular organisms and annotation systems and are not related to the three-variable function concept.

See also F(x,y,z); vector components; multivariable calculus; vector fields.