The summation of series is one of the basic contents of series, and it is also the hot spot and focus of college entrance examination. In recent years, the college entrance examination has been testing a series of new sums, and more emphasis has been placed on ability, which requires us to solve some different problems and master certain methods and skills. However, the common method for students to deal with such problems is mathematical induction, and the amplification of general inequalities is often completed halfway. Inspired by this, the author proves the inequality in the form of sequence, which not only flexibly uses the summation test method, but also scales the proof.

Skills. Using recursive formula to analyze the general term and pass a few out is a method that students have mastered; It is a problem that the author of this paper tries to discuss that the inequality can be proved in the form of sum series through reasonable scaling. This paper analyzes and gives several effective examples of solving problems, so that students can allow such practice communication when solving problems, flexibly use the series knowledge they have learned, skillfully enlarge and approach the series, purposefully "rush" to the "goal" and work it out simply and quickly. That's it. I'm exhausted.