Hello. Advanced mathematics is difficult in the school life of mathematics, but it is only the foundation of real advanced mathematics. Advanced mathematics in school is relatively simple, so don't worry, it is mainly derivative, partial derivative, differential and integral, and then it is a little more complicated on this basis, such as triple integral and multi-order derivative. As long as you lay a solid foundation, there are laws to follow in mathematics. I hope it will help you and be adopted. Thank you. I wish you a happy life and academic progress.