大师作文网1/1x2+1/2x3+1/3x4+.+1/n(n+1)=?
来源：学生作业帮 编辑：大师作文网作业帮 分类：数学作业 时间：2024/11/19 02:05:00
1/1x2+1/2x3+1/3x4+.+1/n(n+1)=?
1/2x4+1/4x6+1/6x8+…+1/2010x2012
1/2x4+1/4x6+1/6x8+…+1/2010x2012
1/1x2+1/2x3+1/3x4+.+1/n(n+1)
=1-1/2+1/2-1/3+1/3-1/4+···+1/n-1/(n+1)
=1-1/(n+1)
=n/(n+1)
再问： 看我补充，谢谢
再答： 1/2x4+1/4x6+1/6x8+…+1/2010x2012 =1/2(2/2x4+2/4x6+2/6x8+···+2/2010x2012) =1/2(1/2-1/4+1/4-1/6+1/6-1/8+···+1/2010-1/2012) =1/2(1/2-1/2012) =1/2x2011/2024 =2011/4048
=1-1/2+1/2-1/3+1/3-1/4+···+1/n-1/(n+1)
=1-1/(n+1)
=n/(n+1)
再问： 看我补充，谢谢
再答： 1/2x4+1/4x6+1/6x8+…+1/2010x2012 =1/2(2/2x4+2/4x6+2/6x8+···+2/2010x2012) =1/2(1/2-1/4+1/4-1/6+1/6-1/8+···+1/2010-1/2012) =1/2(1/2-1/2012) =1/2x2011/2024 =2011/4048
1x2+2x3+3x4+...+n（n+1）=?
一道简便计算数学题1X2+2X3+3X4+4X5...+n(n+1)一1X2+2X3+3X4+4X5...+2013X2
1/1x2+1/2x3+1/3x4+...+1/n(n+1)怎么算
求使1x2+2x3+3x4+…+n(n+1)
已知无穷数列1x2,2x3,3x4…,n（n+1）,… 求：
1 总体X~N(2,4),X1,X2,X3,X4为样本,则(X1+X2+X3+X4)/4~( )
求线性方程组 x2-x3-x4=0 x1+x2-x3+3x4=1 x1-x2+x3+5x4=-1 x1+2x2-2x3+
X1+2X2-X3+X4=1
(x1,x2,x3,x4,x5,x6)来自正态总体N(0,1),Y=(x1+x2+x3)^2+(x4)^2+(x5)^2
X1,X2,X3,X4是总体N(0,1)的样本,则: X1-X2+X3-X4服从什么分布?
根据式子n(n+1)分之1=n(n+1)分之（n+1)-n=n分之1-n+1分之1计算1x2分之1+2x3分之1+3x4
数学题目,求速度1x2十2x3+…+100x101=1x2+2x3+…+n（n十1） 1x2x3+2+3x4+…+n(n