S4 S8-S4 S12-S8 S16-S12 成等差数列的原因

S4 S8-S4 S12-S8 S16-S12 成等差数列的原因 数列推导设等差数列An的前n项和为Sn,则S4,S8-S4,S12-S8,S16-S12成等差数列,设等差数列An的前n项和为Sn,则S4,S8-S4,S12-S8,S16-S12成等差数列,类比以上结论有:设等比数列Bn的前n项积为Tn,则T4,T8/T4,T12/T8,T16/T 设Sn是等差数列an的前n项和,s4/s12=1/6 则s8/s16=? 设等差数列An的前n项和为Sn,则S4,S8-S4,S12-S8,S16-S12成等差数列,类比以上结论有设等比数列Bn的前n项积为Tn,则T4,,,T16/T12成等比数列 等差数列中,S8-S4=12,求S12=? 等差数列中,S4=S8,则S12=_____. 已知等差数列{an}中的前n项和为Sn,且S4/S8=1/3,那么S8/S16等于? 设Sn是等差数列{an}的前n和,若S4/S8=1/3则S8/S16=? 设等差数列{an}的前n项和Sn,且S4/S8=1/3,则S8/S16=? 已知等比数列的前n项和为sn,且s4/s8=1/17,那么s8/s16= 设等比数列｛an｝的前n项和为Sn,若S8/S4=3,则S12/S8=? 已知等差数列an的前n项和为Sn,S4/S8=1/2,那么S8/S12=? 设等比数列{an}前n项和为Sn,若S8:S4=2:3,则S12:S4=?9 在等差数列{an}中,S4=6,S8=10,则S12= sn为等差数列an的前n项和,S8-S4=12,则S12 等差数列{an}中,S4=32,S8=56,则S12=? 等差数列{an},s4=7,s12=90,则s8等于? 在等差数列｛an｝中,已知S4=4,S8=16,则S12