1. In the mathematics of functions, an argument is the dependent variable. For example, in the function f (x) = x ² + 3, x is the argument.

2. In complex numbers, an argument is the angle between ZO, where Z is the point representing a complex number on an Argand diagram and O is the origin, and the real axis.

3. An argument is also a mathematical proof, possibly an informal one. See logic.