UC知道1/2*3+1/3*4+1/4*5……+1/48*49+1/49*50是多少
来源：百度知道 编辑：UC知道 时间：2024/05/28 11:34:49
速度 急急急 5分钟内
1/2*3+1/3*4+1/4*5……+1/48*49+1/49*50
=(1/2)-(1/3)+(1/3)-(1/4)+(1/4)-(1/5)+...+(1/49)-(1/50)
=(1/2)-(1/50)
=24/50
=12/25.
1/2*3+1/3*4+1/4*5……+1/48*49+1/49*50
=(1/2-1/3)+(1/3-1/4)+……+(1/49-1/50)
中间抵消
=1/2-1/50
=12/25
上式=1/2-1/3+1/3-1/4……+1/49-1/50
=1/2-1/50
=49/100
=1/2-/1/3+1/3-1/4+...+1/49-1/50
=1/2-1/50
=49/100
原式=1/2-1/3+1/3-1/4........+1/49-1/50=1/2-1/50=12/25
1+1/2+1/3+.....+1/n
1+1/2+1/3+...+1/100
1-1/2+1/3-.....-1/10
(1+1/2+1/3+1/4)×
1+1/(1+2)+1/(1+2+3)+...+1/(1+2+3+...+100)
1+1/(1+2)+1/(1+2+3)+-------+1/(1+2+3+----+100)
(1/2005-1)(1/2004-1)........(1/3-1)(1/2-1)
1+1/2+1/3+.....+1/2005][1/2+1/3+.......+1/2006]-[1/2+1/3+......+1/2005][1+1/2+1/3+1/2006]
(1-1/2-1/3-...-1/2001)*(1/2+1/3+...1/2002)-(1-1/2-1/3-...1/2002)*(1/2+1/3+...+1/2001)
1/1+1/2+1/3+1/4+。。。。+1/N 是多少