问题 选择题
lim
n→∞
[n(1-
1
3
)(1-
1
4
)(1-
1
5
)…(1-
1
n+2
)]等于(  )
A.0B.1C.2D.3
答案

lim
n→∞
[n(1-
1
3
)(1-
1
4
)(1-
1
5
)(1-
1
n+2
)]

=

lim
n→∞
[n×
2
3
×
3
4
×
4
5
×…×
n+1
n+2
]

=

lim
n→∞
2n
n+2

=2.

故选C.

单项选择题
问答题 简答题