1. Warm and solid knowledge teaching method can organically combine old and new knowledge, so that students can naturally acquire new knowledge from reviewing old knowledge.

2. Introduction by analogy. Analogy acceptance refers to using known mathematical knowledge to analogize unknown new mathematical knowledge and using simple mathematical phenomena to analogize complex mathematical phenomena, so as to visualize abstract problems, arouse students' rich associations, mobilize students' non-intellectual factors and stimulate students' thinking activities.