The codomain of a function is the set into which all of the output of the function is constrained to fall. It is denoted by Y in the notation f: X → Y, where X is the domain of the function. The range of a function is the set of all possible output values, while the domain is the set of all possible input values. The codomain is related to the range, but they are not necessarily the same. The range is the set of all actual output values, while the codomain is the set of all possible output values.
For example, consider the function f(x) = √x. The domain of f is all non-negative real numbers, and the codomain is also all non-negative real numbers. However, the range of f is only the non-negative real numbers greater than or equal to zero.
It is important to note that the domain is an essential part of the function, and every function has a domain.
