Names of function

Question

For any function that converts/computes some integer into another integer or be it a real number to another real number. What is the correct teminology to use for this kind of function? I can't think of it as being a mapping function, seems that wikipedia describes mapping function as something else involving more complex topics. Im no map wiz.

For example $f(x) = 2x$, where $x \in \mathbb{N}_+$ or $\mathbb{Z}_+$ (for any positive integer in the input domain) the function transforms $x$ into one number in the range of even positive integers.

How can I refer to this function? Transform function? Mapping function? Does it have a special name? Say I have several functions that use $f(x)$ later on. $g(x) = f(x)+h(x)$ etc.. does $g(x)$ have a special name other than $f(x)$ or... I would like some simple answer on this.

Thanks

Answer 1

A function has three ingredient, Domain, Range and an assignment.

the notation $ f:A\to B$ where $f$ is the name of the function, $A$ is the domain and $B$ is the range, explains everything.

Of course, we have to clearly define the output in terms of the input to have a well-defined function.

Answer 2

3 components : Domain, Range, and Co-domain Domain = x value Co-domain = y value (result) Range = Bunch of real numbers, Co-domain is a part of this That's what i know, have nice day !