Trigonometric functions must be mastered. The more you know, the better you always make an appointment. Secondly, we should master some advanced calculation skills (this is to test our usual experience and grasp, learn more and imitate more); Another suggestion is that if you are determined to make achievements in the physics competition, you'd better learn simple calculus as soon as possible, and your understanding of physics will take a huge step. There is a set of competition courses that I personally think is very good: physics course of middle school Olympic Games: mechanics/electricity/experiment. . . It was written by Cheng Jiafu, which is very good and powerful, but only if you know calculus ~ ~ ~ Finally, I wish you progress in your study ~!