restricted-domain function
nounUK /rɪˈstrɪktɪd dəˈmeɪn ˈfʌŋkʃən/
US /rɪˈstrɪktɪd doʊˈmeɪn ˈfʌŋkʃən/
A function that only works for some of the numbers you give it.
The square root is a restricted-domain function because it only works for numbers that are zero or bigger.
RELATED WORDS
OTHER MEANINGS
2. A function defined only on a subset of its natural domain, often to keep it one-to-one or avoid undefined values.
To make its inverse a function, the teacher restricted the domain of the parabola.
3. In computing, a function that accepts only a limited set of allowed inputs.
The login function is restricted-domain and rejects any username with symbols.
4. A mathematical rule whose valid inputs are explicitly limited by a stated condition.
The function f(x) = 1/x is a restricted-domain function because x cannot be zero.