F stands for x+ 1, that is, the independent variable plus y=f(x). It can be seen that this F is a calculation method, that is, adding 1 to X, for example, to open the door with a key, and the key is X. The method or process of "turning the key in one direction through the keyhole" represents F, and the process through which the key passes is to open the door, which is equivalent to X in mathematics. F(x)=y is obtained by method F.
Extended data:
Traditional definition
Generally speaking, in a changing process, it is assumed that there are two variables X and Y. If there is a unique Y corresponding to any X, then X is called an independent variable and Y is a function of X. The range of X is called the domain of the function, and the corresponding range of Y is called the domain of the function.
Boundedness, the function f(x) is defined on the interval x, if there is m >；; 0, for all X belonging to the interval X, there is always |f(x)|≤M, then f(x) is bounded on the interval X, otherwise F (x) is unbounded on the interval.
Monotonicity, let the domain of the function f(x) be D, and the interval I is contained in D. For any two points on the interval x 1 and x2, when X 1
If for any two points x 1 and x2 on the interval I, when X 1
References:
Baidu Encyclopedia-Function