作业帮高中等差数列题 坐等高人!等差数列{an}前n项和为Sn,am +am+1 +…..+a n+1 =0 (m＜n),则Sm+n =?
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/06 05:01:47
x){zƓ k|}ݳvLhӹB ]%jv\餞';v$*h'j*h?jX( F=s4uv SI*'V:Xm_`g3Pƪ<]=@&X
H 7p9DC l4e@S4P\&(
高中等差数列题 坐等高人!等差数列{an}前n项和为Sn,am +am+1 +…..+a n+1 =0 (m＜n),则Sm+n =?
高中等差数列题 坐等高人!
等差数列{an}前n项和为Sn,am +am+1 +…..+a n+1 =0 (m＜n),则Sm+n =?
高中等差数列题 坐等高人!等差数列{an}前n项和为Sn,am +am+1 +…..+a n+1 =0 (m＜n),则Sm+n =?
am +am+1 +…..+a n+1=（n-m+1）（am +a n+1）/2 =0
所以am +a n+1 =a1+a m+n =0
所以Sm+n =（m+n）(a1+a m+n )/2 =0