纵观近年来全中国各地的高考试卷,我们可以发现等差数列和等比数列的证明(判定)已成为数列问题的一个新亮点.等差数列、等比数列的证明(判定)一般按下面定义或变形式进行:{an}为等差数列an+1-an=d(常数)an+an+2=2an+1(n∈N*)an=kn+b(k,b为常数)Sn=An2+Bn(A,B为常数);{an}为等比 Looking at the examination papers in various parts of the country in recent years, we can see that the proofs (decisions) of arithmetic series and geometric series have become a new highlight of the series problem. The proofs (decisions) of equal numbers and geometric series are generally shown below. Definitions or variants: {an} is an arithmetic sequence an+1+1=an=d (constant) an+an+2=2an+1 (n∈N*) an=kn+b (k, b is a constant) Sn=An2+Bn (A, B are constants); {an} is equal