题目内容
观察下列式子:1+| 1 |
| 22 |
| 3 |
| 2 |
| 1 |
| 22 |
| 1 |
| 23 |
| 5 |
| 3 |
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 7 |
| 4 |
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 1 |
| 20112 |
分析:由已知中,1+
<
,1+
+
<
,1+
+
+
<
,…,观察分析不等式两边数的变化趋势,归纳其中规律后,推断出1+
+
+
+…+
<
,将n=2011代入得到答案.
| 1 |
| 22 |
| 3 |
| 2 |
| 1 |
| 22 |
| 1 |
| 23 |
| 5 |
| 3 |
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 7 |
| 4 |
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 1 |
| n2 |
| 2n-1 |
| 2 |
解答:解:由已知中的式子:
1+
<
=
,
1+
+
<
=
,
1+
+
+
<
=
,
…,
我们可以推断
1+
+
+
+…+
<
故1+
+
+
+…+
<
=
故答案为:
1+
| 1 |
| 22 |
| 3 |
| 2 |
| 2×2-1 |
| 2 |
1+
| 1 |
| 22 |
| 1 |
| 23 |
| 5 |
| 3 |
| 2×3-1 |
| 3 |
1+
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 7 |
| 4 |
| 2×4-1 |
| 4 |
…,
我们可以推断
1+
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 1 |
| n2 |
| 2n-1 |
| 2 |
故1+
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 1 |
| 20112 |
| 2×2011-1 |
| 2011 |
| 4021 |
| 2011 |
故答案为:
| 4021 |
| 2011 |
点评:本题考查的知识点是归纳推理,其中根据已知的不等式,推断出1+
+
+
+…+
<
是解答本题的关键.
| 1 |
| 22 |
| 1 |
| 32 |
| 1 |
| 42 |
| 1 |
| n2 |
| 2n-1 |
| 2 |
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