If the teacher doesn't grasp the key points (this is the case in our school), then we should do more questions on the basis of understanding the examples, and refer to the papers of previous years, so that you can see some rules of giving questions, and some questions will have similar questions in the papers of previous years, because those contents will be tested. For example, you want to take the derivative test, but you did badly in the derivative test of general functions. Therefore, the derivative test generally takes the derivative of implicit function, parametric function or variable upper limit integral. If there is a mid-term exam, the first two estimates have already been tested, so this time it is almost necessary to test the derivative of the upper limit integral.

The examples given by the teacher in class are also very important, which will include some important problem-solving methods.

For example, to find definite integral, besides method of substitution and integration by parts, we must know and use the integral characteristics of odd function, even function and periodic function, and we must also remember some integral formulas outside the basic integral table in the book, such as what the original function of secx is, so as to do well in the exam.