题目内容
已知函数
=
,数列
满足
,
。(12分)
(1)求数列
的通项公式;
(2)令
-
+
-
+…+
-
求
;
(3)令
=
(
,
,![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108473411.png)
+
+
+┅
,若
<
对一切
都成立,求最小的正整数
。
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108208447.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108224562.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108239480.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108255370.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240051082701015.png)
(1)求数列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108239480.png)
(2)令
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108302549.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108317432.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108333426.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108348418.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108364486.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108380485.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108395373.png)
(3)令
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108411364.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108426486.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108442492.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108458431.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108473411.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108489325.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108504349.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108520360.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108411364.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108551388.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108582615.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108582529.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108598337.png)
(1)
(2)
(3)1009
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108614692.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108645873.png)
试题分析:(1)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108660898.png)
又
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108255370.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108614692.png)
(2)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108707502.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108723475.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108738603.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108754659.png)
=
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108770854.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108785734.png)
(3)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108816947.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108816350.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108832761.png)
∴9
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108863523.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824005108598337.png)
点评:本小题综合考查数列的通项公式和前n项和公式的求解,考查学生对裂项法求和的掌握,考查学生的运算求解能力.
![](http://thumb.zyjl.cn/images/loading.gif)
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