1, the question type of inequality, equation or function, think directly before establishing the relationship between them. Consider the domain first, and then use the "three-in-one theorem".

2. When learning elementary functions with parameters, we should grasp the characteristics that no matter how the parameters change, some properties remain unchanged. Such as the fixed point of a function, the symmetry axis of a quadratic function, etc.

3. Transcendence appears in the zero-seeking function, and the thinking method of combining numbers and shapes is preferred.

4. In the problem of constant establishment, using the image properties of quadratic function and the idea of maximum value in the closed interval of function flexibly, the discussion can be transformed into a maximum problem or a constant establishment problem of quadratic function.

5. When choosing to fill in the blanks, the special value method should be preferred.

6. In the problem of finding the maximum value by using the geometric meaning of distance, the shortest line segment between two points should be considered first, and the minimum value of the sum of distances is often found by using quadratic conclusions; The difference between two sides of a triangle is smaller than the third side, which is often used to find the maximum distance difference.

7. To find the range of parameters, it is necessary to establish inequalities or equations about parameters, and use the range of functions to define or solve inequalities. In the process of formula conversion, the method of separating parameters should be given priority.

8. In solving the triangle problem, knowing three conditions will definitely solve other unknown conditions, which is called knowing three to choose one for short.

9. When calculating the eccentricity of hyperbola or ellipse, it is only necessary to establish the relationship equation between A, B and C. ..