(1/1000-1)×(1/999-1)×(1/998-1)×...×(1/2-1)

问题描述:

(1/1000-1)×(1/999-1)×(1/998-1)×...×(1/2-1)

(1/1000-1)×(1/999-1)×(1/998-1)×...×(1/2-1)
=(-1)^999×(999/1000)×(998/999)×(997/1008)×…×(1/2)
=-1/1000