From personal experience, we should deduce the mathematical formula of senior high school ourselves, master its mathematical ideas first, and then deduce it ourselves, so as to cope with the exam more conveniently. Of course, you have to learn to deduce mathematical formulas yourself, but you don't have to deduce them before you calculate them in the exam. Remember those simple or commonly used conclusions.

There are many knowledge points in high school mathematics, most of which are closely related, but a few of them are loose. Therefore, I suggest that when studying high school mathematics, we must follow the teacher's ideas in class, master the teacher's deduction methods in class, and take more notes on methods; Derive formulas or conclusions actively after class, so that you can not only understand the derivation process, but also deepen your understanding and proficiency in formulas; After that, you should memorize the formula or conclusion (memorization here is different from rote memorization, it is based on derivation, so even if you can't remember clearly, you can deduce the correct conclusion yourself). Through such study, I believe your math will be greatly improved.