跪求这些题的答案!!!!!

2024-12-27 08:10:29
推荐回答(1个)
回答1:

=1/2(1-1/3+1/3-1/5+...+1/2003-1/2005)
=1/2(1-1/2005)
=1/2*2004/2005
=1002/2005