2. It is mainly to remember the error-prone points of some concepts (the first day is mainly based on basic concepts)

3. Remember some questions that are not in the textbook but are often tested, such as absolute values. You can remember more questions that you can't master well.

4. Write down some supplementary contents in the teacher's class or some good problems encountered in the information book.

The last point is very important. Taking notes is to help you master your mistakes and important knowledge. It is more important to review and ponder repeatedly than to take notes.