Argument of a function is number, which can be put to formula of a function. Value of a function is number, which can be obtain from formula of a function. Example. Not allowed divide by 0. Numbers 0, 1 are arguments of a function f. Number 2 are not argument of a function f, because when put 2 to formula of function f then obtain expression without any sense (divide by zero}). Numbers -2, -4 1/2 are values of a function f.