Question

What is function and write it function

Answer 1

Explanation:

A function relates an input to an output. It is like a machine that has an input and an output. And the output is related somehow to the input. f(x) "f(x) = ... " is the classic way of writing a function.

Answer 2

Function definition

 

A technical definition of a function is: a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output.

This means that if the object xx is in the set of inputs (called the domain) then a function ff will map the object xx to exactly one object f(x)f(x) in the set of possible outputs (called the codomain).

The notion of a function is easily understood using the metaphor of a function machine that takes in an object for its input and, based on that input, spits out another object as its output.

A function is more formally defined given a set of inputs XX (domain) and a set of possible outputs YY (codomain) as a set of ordered pairs (x,y)(x,y) where x∈Xx∈X and y∈Yy∈Y, subject to the restriction that there can be only one ordered pair with the same value of xx. We can write the statement that ff is a function from XX to YY using the function notation f:X→Yf:X→Y.