Sharks, grizzly bears and big cats may strike fear into your heart and limbic brain, but they do not even come close to being the deadliest animals on earth. Of the top ten deadliest creatures to humans most are smaller than a silver dollar! One of the few with scary fangs will likely surprise you.
Functions assign outputs to inputs. The domain of a function is the set of all possible inputs for the function. For example, the domain of f(x)=xÂ² is all real numbers, and the domain of g(x)=1/x is all real numbers except for x=0. We can also define special functions whose domains are more limited.
Domain definition. The domain of a function is the set of its possible inputs, i.e., the set of input values where for which the function is defined. In the function machine metaphor, the domain is the set of objects that the machine will accept as inputs. For example, when we use the function notation $f: \R \to \R$, we mean that $f$ is a function from the real numbers to the real numbers. In other words, the domain of $f$ is the set of real number $\R$ (and its set of possible outputs or codomain is also the set of real numbers $\R$).