(1-1/2x2)(1-1/3x3)(1-1/4x4)x.x(1-1/2013x2013)(1-1/2014x2014

问题描述:

(1-1/2x2)(1-1/3x3)(1-1/4x4)x.x(1-1/2013x2013)(1-1/2014x2014
用因式分解

用平方差
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)……(1-1/2014)(1+1/2014)
=(1/2)(3/2)(2/3)(4/3)……(2013/2014)(2015/2014)
中间约分
=(1/2)(2015/2014)
=2015/4028