题目内容
设等差数列{an}、{bn}的前n项和为Sn、Tn,且
=
,则
=
.
| Sn |
| Tn |
| 2n-3 |
| 5n+2 |
| a6 |
| b6 |
| 1 |
| 3 |
| 1 |
| 3 |
分析:根据等差数列的性质有:S2n+1=(2n+1)an+1,由此可把前n项和Sn转化为项an,由此即可求得答案.
解答:解:由
=
,得
=
=
=
,
所以
=
,
故答案为:
.
| Sn |
| Tn |
| 2n-3 |
| 5n+2 |
| S11 |
| T11 |
| 11a6 |
| 11b6 |
| 2×11-3 |
| 5×11+2 |
| 1 |
| 3 |
所以
| a6 |
| b6 |
| 1 |
| 3 |
故答案为:
| 1 |
| 3 |
点评:本题考查等差数列的性质及其应用,若{an}为等差数列,则:S2n+1=(2n+1)an+1.
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