As far as I know, compulsory math 4 is divided into version A, version B, version Soviet Education and version Beijing Normal University, so I don't know which version of the answer you want! Post personal version A first, please check it, it is the most widely used.
(1) Click to see a larger image. I was told that the picture was not clear, and I was drunk!
(2) After use, please adopt it? ! More and more people, after being answered by others, leave it alone, which is a great blow to their enthusiasm. In particular, it is very troublesome to upload typesetting documents into pictures. Please respect the fruits of others' labor. Thank you!