1, thoroughly understand the theorems and definitions in the book;
2. Be proficient in the exercises in the textbook and be able to draw inferences.
3. Choose more specific extracurricular practice books and strengthen practice.
If you get more than 40 points in the exam, it means that you have a vague grasp of the definition of the theorem. Generally speaking, 80-90 hours is enough to complete the above three items.