1, this part of the knowledge is not difficult, and the natural teacher speaks quickly, but as a result, many students did not understand this chapter at that time. It doesn't matter. Do more questions later and think again. This is the simplest knowledge point in high school.

2, learning methods, my suggestion is that we must understand, these things do not rely on understanding, but also try to think about this topic, what to do, what is the starting point, and what is the idea of answering questions. Only in this way, high school mathematics will simply spend one knowledge point after another. You will be very sad just by reciting.