Special value method is a powerful method to deal with multiple-choice questions of abstract functions. According to the nature of abstract function, choosing a familiar function as a special value can solve most multiple-choice questions.

Example 1 the function f(x) defined on r satisfies f (x+y) = f (x)+f (y)(x, y∈R), when x

How to learn abstract functions well by editing this paragraph?

Familiar with the basic knowledge of functions

The basis of solving abstract function problems is to be familiar with the basic knowledge of functions. If you don't even master the basic knowledge of function, solving abstract function problems can only be empty talk. Specifically, to learn functions well, we must master the properties of commonly used functions. For example, the functions involved in middle school are generally monotonous, parity, bounded and periodic; Common functions include exponential function, logarithmic function, trigonometric function, quadratic function and tick function (y = x+a/x (a >; 0)) and so on.

Flexible choice of solutions to problems

From the introduction of the above solutions, it is not difficult to see that when solving abstract function problems, choosing the right method will often get twice the result with half the effort. For multiple-choice questions, choosing special value method, assignment method and image method can get the answer in a short time and save a lot of time in the exam. The understanding of various methods and the choice of appropriate methods in solving problems need more experience and understanding in the usual study.

These are the materials I found. I'm also a freshman, and I've been gnawing at abstract functions recently. Let's work together.