Function range
From Wikinfo
A function range in mathematics is a description of the possible values produced by a function.
Given a function f: A → B, the set f(A) is called the range of f. The range is not to be confused with the codomain B. Generally the range is only a subset of the codomain.
Example
Let the function f be a function on the real numbers:
- f: R → R
defined by
- f: x → x2
The codomain of f is R, but clearly f(x) never takes negative values, and thus the range is in fact the set R+ -- non-negative reals, ie the interval [0,∞):
- 0 ≤ f(x) < ∞
See also: Function codomain, Function domain, Injective, Surjective, Bijective
References
- Adapted from the Wikipedia article, "Function_range" http://en.wikipedia.org/wiki/Function_range, used under the GNU Free Documentation License
