Mathematics in senior high school belongs to the primary state, so it doesn't need much dialectical thinking and explanation theory, but only needs to apply internal fixed formulas and conclusions. College mathematics needs high thinking ability and understanding ability, and most formulas can't be directly applied, so we need to deduce them ourselves to get correct conclusions.

College mathematics is definitely more difficult than high school mathematics. High school is simple, not thorough and not in-depth. For example, in high school, we can directly apply the formula given in the textbook, but in college, it is different. We need to know how this formula is derived, and we need to know every step of its derivation process. College mathematics is also called advanced mathematics. For example, high school mathematics talks about increasing or decreasing functions, while advanced mathematics talks about monotonic increasing or decreasing. High school talks about prime numbers, and universities talk about prime numbers; High school talks about functional graphics, college talks about functional graphics and so on.

Secondly, the differences of teachers' teaching modes. Senior high school math teachers are slow in giving lectures, ensuring that students understand every knowledge point. Communicate with students frequently, find problems, recommend exercises to students, and make unremitting efforts. I often explain the difficulties of exercises in class, the matching exercise books are updated quickly, and the college entrance examination questions are also predicted for students. However, in universities, classrooms usually have to rush to the next class after class, and there is too little time between classes to answer questions for students. Due to the tight class hours, there are basically no exercises to explain the class. Teachers will recommend books, but not exercises, and will not give students papers and exercises. Students should find their own problems or go to the library to study.