分子加到多少啊
分母=(1-1/1004)(1-1/1005)(1-1/1006)(1-1/1007)···(1-1/2006)
=1003/1004*1004/1005*1005/1006*1006/1007*.*2005/2006
=1003/2006
分子加到多少啊
分母=(1-1/1004)(1-1/1005)(1-1/1006)(1-1/1007)···(1-1/2006)
=1003/1004*1004/1005*1005/1006*1006/1007*.*2005/2006
=1003/2006