问题 填空题
lim
n→∞
(
n2+2n
-n)
=______.
答案

原式=

lim
n→∞
(
n2+2n
-n)(
n2+2n
+n)
n2+2n
+n

=

lim
n→∞
2n
n2+2n
+n

=

lim
n→∞
2
1+
2
n
+1

=1.

故答案是1.

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