等比数列及前n项和知识填空:1、几个重要的概念:(1)等比数列:_______________________________________________(2)等比中项:_______________________________________________2、等比数列的通项与前n项和的公式:递推关系__________________________________通项公式__________________________________前n项和的公式__________________________________等比中项的公式__________________________________3、等比数列的判断方法:(1)定义法_____________________________________________________(2)中项法_____________________________________________________(3)通项公式法_________________________________________________(4)前n项和的公式法___________________________________________4、等比数列的基本性质:(1)(2)(3)(4)5、数列常用的求和方法:(1)公式求和法:__________________________________________________(2)倒序相加法:__________________________________________________(3)错位相减法:__________________________________________________(4)分组求和法:__________________________________________________(5)裂项相消法:__________________________________________________例题分析:例2(1)(2)(3)等比数列及前n项和1、选择题:2、填空题:(1)(2)3、解答题: