题目内容：

(1/2004 -1)(1/2003 -1)(1/2002 -1).(1/1001 -1)(1/1000 -1)
文字说.(2004分之1 减1)(2003分之1 减1)(2002分之1 减1)...(1001分之1 减1)(1000分之1 减1)

优质解答

(1/2004 -1)(1/2003 -1)(1/2002 -1).(1/1001 -1)(1/1000 -1)
=(-2003/2004)(-2002/2003)(-2001/2002)...(-1000/1001)(-999/1000)
=(-1)^1005*999/2004
=-999/2004