求(2/n方+4/n方+…+2n/n方)的极限,

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求(2/n方+4/n方+…+2n/n方)的极限,求(2/n方+4/n方+…+2n/n方)的极限,求(2/n方+4/n方+…+2n/n方)的极限,=2*(1+2+……+n)/n²=2*[n(n

求(2/n方+4/n方+…+2n/n方)的极限,
求(2/n方+4/n方+…+2n/n方)的极限,

求(2/n方+4/n方+…+2n/n方)的极限,
=2*(1+2+……+n)/n²
=2*[n(n+1)/2]/n²
=(n+1)/n
=1+1/n
n趋于无穷则1/n趋于0
所以极限=1+0=1

(2+n)n/2n^2
lim(2+n)n/2n^2
=lim(2n+n^2)/2n^2
=lim(1/n+1/2)
=1/2

分子等差数列求和下 易得 答案为1