(2014?呼和浩特一模)數(shù)列{an},已知對任意正整數(shù)n,a1+a2+a3+…+an=2n-1,則a12+a22+a32+…+an2 等于( ?。?A.(2n-1)2 B.13(2n?1) C.13(4n?1) D.4n-1
(2014?呼和浩特一模)數(shù)列{a
n},已知對任意正整數(shù)n,a
1+a
2+a
3+…+a
n=2
n-1,則a
12+a
22+a
32+…+a
n2 等于( ?。?br/>A. (2
n-1)
2B.
(2n?1)C.
(4n?1)D. 4
n-1
數(shù)學人氣:551 ℃時間:2019-10-17 02:27:04
優(yōu)質解答
∵a
1+a
2+a
3+…+a
n=2
n-1…①
∴a
1+a
2+a
3+…+a
n-1=2
n-1-1…②,
①-②得a
n=2
n-1,
∴a
n2=2
2n-2,
∴數(shù)列{a
n2}是以1為首項,4為公比的等比數(shù)列,
∴a
12+a
22+a
32+…+a
n2=
=
(4n?1),
故選C.
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