1 -2/1 3/1 -4/1 5/1 -6/1 7/1 -8/1 9/1 -10/1 11/1 -12/1 13/1 -14/1_数学解答

1 -2/1 3/1 -4/1 5/1 -6/1 7/1 -8/1 9/1 -10/1 11/1 -12/1 13/1 -14/1 15/1

人气：418 ℃　时间：2019-10-20 20:12:04

解答

利用：1-1/2+1/3-1/4……+1/(2n-1)-1/2n=1/(n+1)+1/(n+2)+……1/2n所以：(1-1*2+1/3-1/4+1/5-.+1/1993-1/1994)/[1/(1+1995)+1/(2+1996)+.+1/(997+2991)]=(1/998+.+1/1994)/[1/(1+1995)+1/(2+1996)+.+1/(997+2991)]=(...