题目
题型:武汉模拟难度:来源:
1 |
12 |
1 |
22 |
1 |
22 |
1 |
32 |
1 |
32 |
1 |
42 |
1 |
n2 |
1 |
(n+1)2 |
S1 |
S2 |
Sn |
A.
| B.
| C.
| D.
|
答案
S1 |
1+1+
|
3 |
2 |
S2 |
1+
|
7 |
6 |
S3 |
1+
|
13 |
12 |
S4 |
1+
|
21 |
20 |
猜想:
Sn |
1 |
n |
1 |
n+1 |
∴S=
S1 |
S2 |
Sn |
=1+1-
1 |
2 |
1 |
2 |
1 |
3 |
1 |
n |
1 |
n+1 |
=n+1-
1 |
n+1 |
=
n2+2n |
n+1 |
故选:B.
核心考点
试题【设S1=1+112+122,S2=1+122+132,S3=1+132+142…,Sn=1+1n2+1(n+1)2,设S=S1+S2+…+Sn,其中n为正整数,】;主要考察你对数据的整理与描述等知识点的理解。[详细]
举一反三
|
1 |
2 |
|
|
1 |
3 |
|
|
1 |
4 |
|
则第n个式子是______.