Definition:Complex Function
Definition
A complex function is a function whose domain and codomain are subsets of the set of complex numbers $\C$.
Independent Variable
Let $f: \C \to \C$ be a complex function.
Let $\map f z = w$.
Then $z$ is referred to as an independent variable (of $f$).
Dependent Variable
Let $f: \C \to \C$ be a complex function.
Let $\map f z = w$.
Then $w$ is referred to as the dependent variable (of $f$).
Examples
Square Function
Let $f: \C \to \C$ be the function defined as:
- $\forall z \in \C: \map f z = z^2$
This is a complex function.
Imaginary Part
Let $f: \C \to \C$ be the function defined as:
- $\forall z \in \C: \map f z = \map \Im z$
where $\map \Im z$ denotes the imaginary part of $z$.
$f$ is a complex function whose image is the set of real numbers $\R$.
Principal Argument
Let $f: \C \to \C$ be the function defined as:
- $\forall z \in \C: \map f z = \Arg z$
where $\Arg z$ denotes the principal argument of $z$.
$f$ is a complex function whose image is the set of real numbers $\R$.
Also see
- Results about complex functions can be found here.
Sources
- 1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.) ... (previous) ... (next): $2$: Functions, Limits and Continuity: Variables and Functions
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): complex function (function of a complex variable)
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): complex function (function of a complex variable)
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): function of a complex variable
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): complex function