已知:12+22+32+…+n2=1/6n(n+1)(2n+1),试求22+42+62+…+1002
已知:12+22+32+…+n2=1/6n(n+1)(2n+1),试求22+42+62+…+1002
已知12+22+32+….n2=(1/6)n(n+1)(2n+1),试求22+42+62….+502的值(写过程)
12+22+32+42+……+n2=n+(n+1)(2n+1)/6为什么?
证明:12+22+32+……+n2=1/6n(n+1)(2n+1)
12+22+32+42+52+62+72+82+…+n2=n(n+1)(2n+1)/6
大一求极限lim(n/(n2+1)+n/(n2+2^2)+……+n/(n2+n2))
已知12+22+32+42+52+-------+n2=6分之1XnX(n+1)(2n+1)试求22+42+62+---
请问如何证明lim(n→∞)[n/(n2+n)+n/(n2+2n)+…+n/(n2+nn)]=1,
已知:12+22+32+…+n^2=16n(n+1)(2n+1),试求22+42+62+…+1002
计算:12-22+32-42+52-62+…+n2-(n+1)2=________.(n属于奇数)
求极限lim((n+1)/(n2+1)+(n+2)/(n2+2)+...+(n+n)/(n2+n)),n趋近无穷
1.求lim[1/(n2+n+1)+2/(n2+n+2)+.+n/(n2+n+n)][n趋于无穷][n2为n的平方]