tfsf.net
当前位置:首页>>关于1/1x3+1/3x5+1/5x7.....1/2009x2010+1/2011x2013的资料>>

1/1x3+1/3x5+1/5x7.....1/2009x2010+1/2011x2013

1/1x3+1/3x5+1/5x7..1/2009x2011+1/2011x2013=1/2*1-1/3+1/3-1/5+1/2009-1/2011+1/2011-1/2013)=1/2*1-1/2013=1006/2013

原式=1/2*(1-1/3)+1/2*(1/3-1/5)+……+1/2*(1/2009-1/2011)=1/2*(1-1/3+1/3-1/5+……+1/2009-1/2011)=1/2*(1-1/2011)=1005/2011

=(1-1/3+1/3-1/5+1/5……+1/2011-1/2013)=(1-2013)除以2/2013=2012/2013

1/(1x3)+1/(3x5)+1/(5x7)++1/(2011x2013)=1/2 x[2/(1x3)+2/(3x5)+2/(5x7)++2/(2011x2013)]=1/2 x[1-1/3+1/3-1/5+1/5-1/7++1/2011-1/2013]=1/2 x[1-1/2013]=1/2 x[2012/2013]=1006/2013

1*3分之x+3*5分之x+5*7分之x++2011*2013分之x=2012x/2(1-1/3)+x/2(1/3-1/5)+x/2(1/5-1/7)+x/2(1/2011-1/2013)=2012x/2(x-1/2013)=20121006x/2013=2012x=4026

1/1x3+1/3x5+1/5x7++1/2007x2009 =1/2*(1-1/3)+1/2(1/3-1/5)+1/2(1/5-1/7)++1/2(1/2007-1/2009) =1/2*(1-1/3+1/3-1/5+1/5-1/7++1/2007-1/2009) =1/2*2008/2009 =1004/2009

=(2/1*3+2/3*5+2/2008*2010)/2=(1-1/3+1/3-1/5+1/5-1/7……+1/2008-1/2010)/2=(1-1/2010)/2=200

1/(1*3)+1/(3*5)++1/(2011*2013)=(1/2)(1-1/3+1/3-1/5++1/2011-1/2013)=(1/2)(1-1/2013)=(1/2)(2012/2013)=1006/2013

1/1x3+1/2x4+1/3x5++1/2011x2013=1/2*(1-1/3+1/2-1/4+1/3-1/5+,,,,+1/2010-1/2012+1/2011-1/2013)=1/2*(1+1/2-1/2012-1/2013)=1/2*(6071209/4050156)=6071209/8100312

1/1x3十1/3x5十1/5x7十+1/2011x2013=(1/2)x(1- 1/3+ 1/3 -1/5 +..+1/2011 -1/2013)=(1/2)x(1-1/2013)=(1/2)x (2012/2013)=1006/2013

相关文档
网站首页 | 网站地图
All rights reserved Powered by www.tfsf.net
copyright ©right 2010-2021。
内容来自网络,如有侵犯请联系客服。zhit325@qq.com