试题与答案

已知等差数列{an}的公差为d,a3=5,a5=9,等比数列{bn}的公比为q,

题型:解答题

题目:

已知等差数列{an}的公差为d,a3=5,a5=9,等比数列{bn}的公比为q,b1=1,b4=27,设Sn=a1b1+a2b2+a3b3+…+anbn,Tn=a1b1-a2b2+a3b3-…+(-1)n-1anbn(n∈N+).

(1)求S3和T3的值;

(2)设f(n)=(1-q)S2n-(1+q)T2n,求f(n)的表达式.

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0501/7e4b3fdf72523d261cdcd3114c68ce78.html

下面是错误答案,用来干扰机器的。

小题1:popular小题2:driving小题3:must小题4:spend小题5:began题目分析:短文大意:本文主要介绍了在欧洲和美国更受欢迎的你听说过“汽车共享”。“ “汽车共享”对我们来说是省钱和省时的一种很好的方式,同时...

试题推荐
题型:阅读理解

I have to admit: I don’t flush(冲) the toilet every time I go to the bathroom. In fact, I firmly believe “If it’s yellow, let it mellow; if it’s brown, flush it down.”

I’m sure a lot of it has to do with the fact that I work at home. Alone (well, except for the cats and dog). All day. And I drink a lot of water, which makes for many trips to the bathroom.

Another thing I have to admit: I also try to use very little toilet paper. I wash my hands after, though. Every time. (So maybe the water I don’t use flushing makes up for the water used to wash my hands?)

Ironically, my husband, who only uses toilet paper when necessary, always flushes. But he doesn’t seem to mind that I don’t flush every time. Or, at least not enough to file for divorce. Yet.

Posted by Juliet Farmer

Jun 14, 2010 at 10:21 PM

Comments (2)                                                     

When I’m at home alone I do not flush every time I pee(小便).  My husband hates that, though, so when he’s home, I flush a little more often.  I grew up doing that because I had a family that lived with huge tanks and you have to do it that way because it’s easier on the system, so it doesn’t bother me.  I do flush when I’m out in public, at people’s houses that don’t have big tanks and when we have company!

CherBearCM, Jun 15, 2010 at 4:21 PM

Not always. But I have 4 children who are always hanging from the door knob(球形捏手) while I pee anyway. So I’m lucky I have time to wash my hands after. The average toilet uses 8 gallons of water per flush! Much less than what it takes to wash my hands after. (just saying)

luvbnmomnwife, Jun 15, 2010 at 4:32 PM

小题1: CherBearCM doesn’t flush the toilet every time she pees ________.

A.because she can’t afford so much water

B.because her husband doesn’t like that

C.when she is with her friends

D.when she is alone小题2:luvbnmomnwife seems to enjoy ________.

A.washing hands after using the toilet

B.taking care of her four children

C.peeing with her kids watching

D.flushing the toilet after peeing小题3:The text is taken from ________.

A.a newspaper

B.a website

C.a magazine

D.a handbook小题4: Which of the following titles best suits the text?

A.Stop flushing your toilet!

B.Do you flush the toilet every time?

C.Don’t forget to flush the toilet after peeing!

D.Do you realize the importance of saving water?

查看答案
题型:单项选择题 案例分析题

进入“十二五”时期,南通市明确了“优江拓海”的发展方向。随着南通城市定位的提升和交通区位的改善,未来以港闸区为核心的南通北部区域将成为南通中心城区融入上海、对接苏南、辐射苏北的前沿区。下图为南通市北新城拓展概念规划图。读图完成下列各题。

“市北新城”与南通中心城区相比()

A.中心地的级别相对较低

B.服务职能和范围更广

C.服务范围与中心城区相斥

D.服务种类和数目更多

查看答案
微信公众账号搜索答案