问题 选择题
(文)
lim
n→∞
n2+2n-1
n2-n-1
=(  )
A.1B.-
1
3
C.-1D.-
7
12
答案

lim
n→∞
n2+2n-1
n2-n-1
=
lim
n→∞
1+
2
n
-
1
n2
1 -
1
n
-
1
n2
=
1+0-0
1-0-0
=1,

故选A.

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