根据等差数列的前n项和公式可得S11= 11(a1+a11)2 = 11×2a62 =11a6=2013, 所以a6=183. 【考点提示】 本题是一道关于等差数列的题目,解答本题的关键是熟练掌握等差数列的前n项和公式和性质; 【解题方法提示】 根据等差数列的前n项公式可得S11= 11(a1+a11)2 ,接下来你有思路了吗? 结合等差数列的性质...
S11=(a1+a11)11/2=22a1+a11=42a6=a1+a11=4a6=2因为是等差数列，所以S11=11a6 所以a6=2因为2xa6=a1+a11,所以5.5xa6=22,a6=4.
S11=11a+11*10/2*d=2211(a+5d)=22a6=a+5d=22/11=2请采纳回答 解析看不懂?免费查看同类题视频解析查看解答 更多答案(3) 相似问题 若{an}为等差数列,Sn是其前n项和,且S11=22π3,则tana6的值为( ) A.3 B.−3 C.±3 D.−33 在等差数列中,S11=22,则a6=_. 已知Sn为等差数列an的前n...
已知等差数列{an}中,前n项的和为Sn,若a3+a9=6,则S11= 33. 相关知识点: 试题来源: 解析 解:由等差数列的求和公式可得S11=(11(a_1+a_(11)))/2=(11(a_3+a_9))/2=(11*6)/2=33故答案为:33 由等差数列的求和公式和性质可得S11=(11(a_3+a_9))/2,代入化简可得....
a2+a10=2a6……同理得出 S11=(a1+a11)+(a2+a10)+(a3+a9)+(a4+a8)+(a5+a7)+a6 =2a6+2a6+2a6+2a6+2a6+a6 =11a6 所以a6=S11/11=56/11 如果用公式的话，S11=na1+n(n-1)d/2=11a1+10*11d/2=11a1+55d=11(a1+5d)∵a6=a1+5d ∴S11=11a6，a6=S11/11=56/11 s11...
ans111198R S1: What time do you get up ?S2: I ... at ... 相关知识点: 试题来源: 解析 [参考词汇】get up,go to school,have lunch/dinner, seven o'clock, quarter, half past six, eleven, eight 范例: S1: What time do you get up? S2: I get up at seven o'clock. ...
等差数列{an}中,S10小于0,S11大于0==>数列{an}的首项a1是小于0的,而公差是大于0的同时,S10 <0 而S11>0也就说明了,a11开始大于0了,a12后面的肯定比a11大,因为公差是大于0的而a10跟a11的大小确定不了!所以,绝对值最小的项有a10或a11 解析看不懂?免费查看同类题视频解析查看解答 更多答案(1) ...
a1=14 a6=-1 an=-3n+17 详细过程如下：
S116R is a non-phosphorylatable variant present in bovine FGF-1 and other members of the human FGF family. We show that the S116R mutation in human FGF-1 is accommodated with no perturbation of biophysical or structural properties, and is therefore an attractive mutation with which to ...
s10=10(a1+a10)/2=5(a1+a10)=5(a5+a6)>0,所以a5+a6>0,s11=11(a1+a11)/2=5.5(a1+a11)=5.5*2a6=11a6<0,所以a6<0, 所以a5>0,所以an<0的最小n值是6 S10