1, boundedness: boundedness of a function is a mathematical term. Let the domain of the function f(x) be d and defined on the set d. If the number K 1 exists, so that f(x)≤K 1 holds for any x∈D, it is said that the function f(x) has an upper bound on d, otherwise, if the number K2 exists, it is F (x). ..
2. Monotonicity: The monotonicity of a function is also called the increase or decrease of the function. When the independent variable of the function f(x) increases (or decreases) in the defined interval, the function value f(x) also increases (or decreases), so the function is said to be monotonous in this interval.
3. Parity: Parity is called parity. Generally speaking, if there is any X in the function domain, there is f(-x)=-? F(x), the function f(x) is called odd function. If for any x in the function definition domain, there is f(-x)=? F(x), the function f(x) is called even function.
4. Continuity: function y=? F(x), when the change of independent variable X is small, the change of dependent variable Y is also small. For example, as long as the time changes little, the temperature changes little. For another example, the displacement of a free-falling body changes with time. As long as the time change is short enough, the displacement change is also small. ? F(x)=f(x0), and the function f is said to be continuous at x0.