1/2+1/6+1/12+1/20+.1/(2005*2006)=?_数学解答

1/2+1/6+1/12+1/20+.1/(2005*2006)=?

人气：160 ℃　时间：2020-04-16 06:59:42

解答

1/2+1/6+1/12+1/20+.1/(2005*2006)
=1-1/2+1/2-1/3+1/3-1/4+……+1/2005-1/2006
=1-1/2006
=2005/2006