First, the basic problem description

1. does not give a specific resolution function, but only gives some known conditions that reflect the characteristics or relations of the function, and solves the basic problems of the resolution function. The function values and parameter values are abstract functions.

2. Because there is no distinguishing function, the understanding of abstract function problem becomes more abstract, and its solution idea is far from that of conventional function (for which analytical formula has been given). This makes most students with weak foundation a headache and becomes one of the difficulties in the function part.

3. This is the most difficult part of the function in senior high school, and it is also a connection point of the function in college advanced mathematics. Because abstract functions have no specific analytical expressions as carriers, it is difficult to understand and learn. However, because this kind of questions can not only examine the concept and nature of functions, but also examine students' thinking ability, they are favored by proposers.

Second, the general method to solve the problem

1. The key to solving the problem of abstract function is to deeply understand and skillfully use the concept and properties of function. Doing this well will help you understand and grasp the essence of abstract function problems, instead of clinging to' unknown analytic function'.

2. The analytical expression of abstract function is unknown, but it is a real function with various concrete and concrete characteristics. In other words, although the function is abstract-the analytic function is unknown, its related characteristics are concrete, and the key is to understand and grasp the latter.