The last question is usually a series or a function, but the first question can often be done. The first problem is usually to find the value of a function or a series. It doesn't need complicated calculation, but it may be a little difficult at first. At this time, several values are often taken. If it is a series, we should consider the case that n is equal to 1. If the topic is related to other items, we should consider the nature of arithmetic and proportionality. The arithmetic difference is that the sum of two terms can be. If it is a function, the zero point of cubic function can't be found, or other kinds of quantities will generally appear. At this time, we should pay attention to simplifying the equation, whether it can be decomposed into the product of several factors, or take special values such as x=- 1, 0, 1, e. And find out some implicit functional relationships. You can also make a few dots, draw dots and draw pictures on the draft paper. You can also consider whether the function has special parity, period, increase or decrease, etc. And make full use of the conditions of the topic. The second question is often to prove an inequality in the topic or to solve an unknown number. At this time, remember to learn from the graphic structure and algebra of functions. Generally, it is a problem to find inequality, with a constant on one side and a new function on the other, and then find the maximum value of the function by derivative.