因为an为等差数列,设公差为d.
an+1- an^2+ an-1=0
an+d-an^2+an-d=0
2an-an^2=0
an=0或2 因为an≠0所以an=2
S2n-1= 2n-1*(a1+a2n—1)/ 2
a2n-1=an+(n-1)* d
a1=an-(n-1)*d
代入S2n-1表达式.解得即可~
因为an为等差数列,设公差为d.
an+1- an^2+ an-1=0
an+d-an^2+an-d=0
2an-an^2=0
an=0或2 因为an≠0所以an=2
S2n-1= 2n-1*(a1+a2n—1)/ 2
a2n-1=an+(n-1)* d
a1=an-(n-1)*d
代入S2n-1表达式.解得即可~