在高中代数第二册讲到无穷递縮等比数列各項和的时候,需要証明下面的一个极限等式:(?),其中 |q|<1。但是在課本的注脚里提到,由于“証明很繁,这里省略不讲”,然而在教学中,往往由于同学們的求知欲望,常常追間,現在我把自己在这次教課中所采用的一个証法写出来,請大家批評指教: In the second volume of algebraic algebra, when we talk about sums of indefinitely recursive geometric sequences, we need to prove one of the following extreme equations: (?), where |q|<1. However, in the footnotes of textbooks, it is mentioned that because “the proof is very complicated, the omission is not mentioned here.” However, in the teaching, because of the students’ desire for knowledge, they often follow suit. Now I have adopted myself in this teaching. One of the proofs is written out. Please criticize and advise: