一、错位相减法的概念及在高考中的地位错位相减法是一种常用的数列求和方法,应用于等比数列与等差数列相乘的形式。形如Sn=an.bn,其中an为等差数列,bn为等比数列;分别列出Sn,再把所有式子同时乘以等比数列的公比,即qSn;然后错一位,两式相减即可。数列求和是数列知识中的重要内容。在学习中我们往往只重视求和公式的掌握及应用,而忽略公式推导过程中所涉及的 First, the concept of dislocation subtraction method and the position in the college entrance examination Displacement subtraction method is a commonly used sequence summation method, applied to the geometric sequence multiplied by the arithmetic sequence. Shape as Sn = an.bn, where an is the arithmetic sequence, bn is the geometric sequence; list Sn, and then all the equations simultaneously multiplied by the geometric ratio of the geometric series, that qSn; then wrong one, two Subtraction can be. Summation of series is an important part of knowledge in series. In learning, we tend to focus only on the mastery and application of the summing-up formula, while ignoring the implications of the formula derivation process