高考数学一轮复习第五章数列5.4数列求和练习含解析20170705125.docVIP

数列求和,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催时间:50分钟 总分：70分 ,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 班级： 姓名： ,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 选择题（共6小题，每题5分，共30分）,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 1.已知等差数列{an}的前n项和为Sn，S5＝－20，则－6a4＋3a5＝(　　),2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 A.－20 B.4 ,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 C.12 D.20,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 【答案】,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 【解析】　因为S5＝－20，所以S5＝5a3＝－20，∴a3＝－4，∴－6a4＋3a5＝－6(a1＋3d)＋3(a1＋4d)＝,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 －3(a1＋2d)＝－3a3＝12.,2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖候逻耐异旷侦咋明畴昆怪火伦吃棵叁笋颓浆边捎撬戌席简窄皿瘸想呈喊锄荤勋潭锄寐痒消内谚去消墓坊滦吃木瞥朗惑霜倍谅催 2.(2012·大纲全国)已知等差数列{an}的前n项和为Sn，a5＝5，S5＝15，则数列的前100项和为(　　),2)＋eq \f(1,2)－eq \f(1,3)＋…＋eq \f(1,100)－eq \f(1,101)＝1－eq \f(1,101)＝eq \f(100,101饲奢博典挖