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解: (1)S1=a1=f (1,2),∴1 S 1=2.当n≥2时,an=Sn-Sn－1,即Sn-Sn－1=-2SnSn－1.∴1 S n-1 S=2,故 {1 S n}是以2为首项,2为公差的等差数列. (2)由 (1)得1 S n=2+ (n-1)·2=2n,Sn=f (1,2n) (n∈N＋),当n≥2时,an=-2SnSn－1=-f (1,2n (n-1). 已知数列 {an}的前n项和为Sn,且满足a1=,an+2SnSn－1=0 (n≥2). (1)判断 {}是否为等差数列?并证明你的结论; (2)求Sn和an; (3)求证:S+S+…+S≤-.

2012年2月24日 · To confirm the player is providing a 1080i signal, you might try connecting the HD-DVD player directly to a hdmi connection on the TV as a test. If that works, then you know the player is functioning?

2024年3月5日 · The model also detects closed eyes or if one eye is open but both eyes are visible. What doesn't work: 1) If a character has one eye covered by something (patch, hair, etc), the model does not recognize it; 2) If there is only one eye in the image with no context that there is another eye. How to use: How to install:

2019年10月25日 · Compared with normal eyes, the Ambrósio’s Relational Thickness horizontal (ARTh), biomechanical corrected IOP (bIOP), stiffness parameter at first applanation (SP A1) were low and the Max Inverse...

2015年5月31日 · 为什么数列an等于Sn-(Sn-1)的具体计算到最后面时还要加a1Sn减去Sn-1最后不是到a2减去a1就完了么？为什么还要加a1？从这里推出那是不是an+1等于(Sn+... 为什么数列an等于Sn-(Sn-1)的具体计算到最后面时还要加a1 Sn减去Sn-1最后不是到a2减去a1就完了么？为什么还 …

2020年11月29日 · Whether my eyes are sensitive to IPS technology or this monitor is crap for my eyes because of it's glowing corners, all I can say is what a shame! I really wanted this upgrade and get a bigger picture with richer images than a washed up 6bit color depth screen I chose in the past exclusively for speed, due to tech limitations from back then.

2017年10月20日 · How did vision begin? What were the important steps in the evolution of eyes? How did eyes differentiate along their various paths, and why?

2007年5月14日 · Hi guys, my boss bought a first gen Toshiba HD DVD player (hd-a1sn). He is trying to get rid of it and said that he would take $100 for it with some HD...

We present experimental results of the trace argon impurity puffing in the Ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and...