帮忙看一下,|1
|1-1/2|+|1/2-1/3|+|1/3-1/4|........|1/2009-1/2008|=???
|1-1/2|+|1/2-1/3|+|1/3-1/4|........|1/2009-1/2008| =1-1/2+1/2-1/3+1/3-1/4...........+1/2008-1/2009 =1-1/2009 =2008/2009