(1-1/2^2)*(1-1/3^2)*(1-1/4^2)*.*(1-1/2002^2)*(1-1/2003^2)

问题描述:

(1-1/2^2)*(1-1/3^2)*(1-1/4^2)*.*(1-1/2002^2)*(1-1/2003^2)

(1-1/2^2)=1/2*3/2
(1-1/3^2)=2/3*4/3
.
(1-1/2^2)*(1-1/3^2)*(1-1/4^2)*.*(1-1/2002^2)*(1-1/2003^2)
=1/2*3/2*2/3*4/3*3/4*5/4*.*2002/2003*2004/2003
=1/2*2004/2003
=1002/2003