10 |
x |
又点A1的横坐标为2,
∴A1(2,5),A2(4,
5 |
2 |
∴S1=2×(5-
5 |
2 |
由题图象知,An(2n,
10 |
2n |
10 |
2n+2 |
∴S2=2×(
10 |
4 |
10 |
6 |
5 |
3 |
∴图中阴影部分的面积知:Sn=2×(
10 |
2n |
10 |
2n+2 |
10 |
n(n+1) |
∵
1 |
n(n+1) |
1 |
n |
1 |
n+1 |
∴S1+S2+S3+…+Sn=10(
1 |
2 |
1 |
6 |
1 |
n(n+1) |
1 |
2 |
1 |
2 |
1 |
3 |
1 |
n |
1 |
n+1 |
10n |
n+1 |
故答案为:
10n |
n+1 |
10 |
x |
10 |
x |
5 |
2 |
5 |
2 |
10 |
2n |
10 |
2n+2 |
10 |
4 |
10 |
6 |
5 |
3 |
10 |
2n |
10 |
2n+2 |
10 |
n(n+1) |
1 |
n(n+1) |
1 |
n |
1 |
n+1 |
1 |
2 |
1 |
6 |
1 |
n(n+1) |
1 |
2 |
1 |
2 |
1 |
3 |
1 |
n |
1 |
n+1 |
10n |
n+1 |
10n |
n+1 |