通项公式是?_______________________________
若m+n=p+s,则:_______________________________
若m+n=2p,则:_______________________________
①_______________________________
②_______________________________
求和公式的特点:_______________________________
通项公式是?_______________________________
若m+n=p+s,则:_______________________________
若m+n=2p,则:_______________________________
①_______________________________
②_______________________________
求和公式的特点:_______________________________
若,则_______________________________
若 ,则_______________________________
已知{}为等差数列,{}又成等比,则公比 _______________________________
已知{}为等比数列,若{+}(0 )也成等比,则公比 _________________
已知 分别是等差(或等比)数列的前m、2m、3m······项和,
则结论是:_______________________________
方法一:累加,所适用题型是:_______________________________
方法二:累乘,所适用题型是:_______________________________
①题型一: 构造方法:_______________________________
②题型二: 构造方法:_______________________________
③题型三: 构造方法:_______________________________
④题型四: 构造方法:_______________________________
⑤题型五: 构造方法:_______________________________
题型四:_______________________________, 方法是_______________________________
分组求和,所适用题型是:_______________________________
并项求和,所适用题型是:_______________________________
形式1:_______________________________
形式2:_______________________________
形式3:_______________________________
形式4:_______________________________
形式5:_______________________________
形式6:_______________________________
形式7:_______________________________
形式8:_______________________________
错位相减,所适用题型是:_______________________________
倒序相加,所适用题型是:_______________________________