yy991女主播名单:1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5 )+...+1/(2000*2001)+1/(2001*2002)=
来源:百度文库 编辑:查人人中国名人网 时间:2024/05/04 19:21:31
1/2*3=1/2-1/3,1/3*4=1/3-1/4,...,
原式=1/1-1/2+1/2-1/3+1/3-1/4+...+1/2000-1/2001+1/2001-1/2002
=1-1/2002=2001/2002
2001/2002
原式=1-1/2+1/2-1/3……-1/2001+1/2001-1/2002=2001/2002
1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5 )+...+1/(2000*2001)+1/(2001*2002)
=1-1/2+1/2-1/3+1/3-1/4+……+1/2001-1/2002
=1-1/2002
=2001/2002