Domääni
Domääni is the Estonian mathematical term for the domain of a function or relation. It denotes the set of input values for which the expression is defined. For a function f: D → Y, D is its domääni; the codomain is Y, and the range is the subset of Y actually reached by f.
Examples help illustrate the concept. For f(x) = sqrt(x − 1), the domääni is { x ∈ R | x ≥ 1
In complex analysis, a function’s domääni is a connected open subset of the complex plane where the
Determining the domääni involves identifying restrictions that come from the expression itself: avoiding division by zero,
The term is standard in Estonian mathematics education and literature for describing where a function is valid