Su Jiaoban 9 which unit of mathematics is the most difficult part of function. In the senior high school entrance examination, function is often used as the final question, as well as multiple-choice questions and grading questions. It is often associated with triangle knowledge, forming a moving point problem. The difficulty coefficient is very large, which tests students' thinking ability and the integration ability of each chapter. Mathematics is a discipline that studies the concepts of quantity, structure, change, space and information, and belongs to a formal science from a certain point of view. Mathematicians and philosophers have a series of views on the exact scope and definition of mathematics. The development history of mathematics can be traced back to ancient civilizations such as ancient Egypt, Mesopotamia, and ancient India, while in ancient Greece, the handling of mathematics was more rigorous.