等差数列中,An为前n项和,am-1+am+1-am^2=0. S2m-1=38. 则m等于什么

为什么等差数列中an=A(2n-1)?An为等差数列前n项和. 等差数列中,An为前n项和,am-1+am+1-am^2=0. S2m-1=38. 则m等于什么 求助~求助~有关数列的填空题~!1已知数列{an}中的前n项和为Sn=3n^2+n+1,则an=________2.在等差数列{an}中,am=n,an=m(m不等于n),a(m+n)=_____________3.等差数列{an}中,a1+a2+.+a50=200,a51+a52+...+a100=2700则公差为________ 1、等差数列{an}的前n项和为Sn,已知am-1+am+1-am^2=0,S2m-1=38,则m=___ 2、已知(an}为等差数列,a1+a3+a...1、等差数列{an}的前n项和为Sn,已知am-1+am+1-am^2=0,S2m-1=38,则m=___2、已知(an}为等差数列,a1+a3+a5=105,a2+a4+a6 等差数列题等差数列an的前n项和为Sn,已知am-1 + am+1 -am^2 =0,S2m-1=38,则m= 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 =? 等差数列{an}中,Sn是其前n项和,公差为d不等于0,(1)若an=m,am=n,求am+n.(2)若S2=S6,求S8 等差数列{an}的前n项和为Sn,已知am-1 +am+1 -(am)^2=0,S2m-1=38,求mM-1,M+1 都是在a的右下角am^2的m是a 右下角的 等差数列AN的前n项和为Sn,若S2m-1/2m-1=10,则am= 等差数列An的前n项和为Sn,a1＝1,S3＝a5,Am＝2011求m 等差数列{An}中,前n项和Sn=an2+（a-1).n+(a+2),则An=为什不能用Sn-Sn-1算 在等差数列{an}中,其前n项和为Sn,若Sn=an2+(a+1)n+a+2,则an= 在等差数列{an}中,其前n项和为Sn,若Sn=an2+(a+1)n+a+2,则an= 等差数列{an}的前n项和为Sn,已知am-1+am+1-am^2=0,S2m-1=38,则m=___ 等差数列{An},的前n项和为Sn,已知Am-1+Am+1-(Am)*2=0,S2m-1=38,则m=? 等差数列{an}的前n项和为Sn,已知am-1+am+1-am^2=0,S2m-1=38,求m 等差数列{an}的前n项和为Sn,已知am-1+am+1-am²=0,S2m-1=38,求m的值 等差数列{an}的前n项和为Sn,已知am-1+am+1-am^2=0,S2m-1=38,则m=___ 尽快好吧