The most important thing to do well is to find a way of thinking. Many students are often at a loss when they encounter a proof problem, and they begin to let their thinking spread infinitely, and finally they are at a loss. For a topic, the questioner has a way of thinking. He tells you his thoughts with conditions, and then lets the problem solver find a conclusion according to the conditions. Therefore, for a proof problem, we must first dig out the known conditions, find some hidden conditions, and then determine the method according to the known conditions. How to determine the method? This needs to be accumulated continuously, and some of them will be summarized in textbooks and teachers' explanations, such as the common auxiliary lines in junior high school geometry, the reduction to absurdity and mathematical induction in senior high school, and the basic methods of finding limits, calculus and matrix problems in universities. In fact, you need to practice more by yourself, and at the same time, you should sum up and draw inferences. Only in this way can you understand a problem well when you see it.

If you don't want to practice, summarize, even attend classes or study, then there is a way: 1, turn yourself into a genius, but it seems that all geniuses like to study; 2. In case of unanswerable questions, list all known conditions and implied conditions, put a bracket on them, and directly deduce the answer. But this method is only useful for a few questions and a few teachers. Many times the teacher will send a big fork.