等差数列中,求证：S奇/S偶=(n+1)/(n-1),n为奇数.

1.S奇=a1+a3+a5+a7+...a(2k+1)=(k+1)a(k+1)
S偶=a2+a4+a6+...+a2k=ka(k+1)
S奇/S偶=(k+1)/k
n=2k+1
S奇/S偶=(n+1)/(n-1).
2.S奇+S偶=S=a1+a2+……+an
S奇/S偶=(n+1)/(n-1)
S奇=(n+1)/2n*S
S偶=(n-1)/2n*S
S奇-S偶=2/2n*S=S/n=(a1+a2+……+an)/n.