A function is a rule for pairing things up with each other. A function has inputs, it has outputs, and it pairs the inputs with the outputs. There is one important restriction to this pairing: Each input can be paired with only one output.Click to see full answer. Similarly, it is asked, what is definition of a function in math?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.Similarly, how do you write a function in math? If you can move a vertical line along the x-axis and only intersect one y at a time, your equation is a function as it follows the only one output for each input rule. Solve your equation for y. For instance, if your equation is y -6 = 2x, add 6 to both sides to get y = 2x + 6. Decide on a name for your function. Similarly one may ask, what is a function in math simple? From Wikipedia, the free encyclopedia. In mathematics, a function is a mathematical object that produces an output, when given an input – it could be a number, a vector, or anything that can exist inside a set of things. So a function is like a machine, that takes values of x and returns an output y.What makes a relation a function?A relation from a set X to a set Y is called a function if each element of X is related to exactly one element in Y. That is, given an element x in X, there is only one element in Y that x is related to. This is a function since each element from X is related to only one element in Y.