各种门锁图片价格:(1+1/2)(1-1/2)(1+1/3)(1-1/3)(1+1/4)(1-1/4)---(1+1/2004)(1-1/2004)

来源:百度文库 编辑:杭州交通信息网 时间:2024/04/29 08:41:11

(1+1/2)(1-1/2)(1+1/3)(1-1/3)(1+1/4)(1-1/4)……(1+1/2004)(1-1/2004)
=(1+1/2)(1+1/3)(1+1/4)……(1+1/2004)*(1-1/2)(1-1/3)(1-1/4)……(1-1/2004)
=(3/2)(4/3)(5/4)……(2005/2004)*(1/2)(2/3)(3/4)……(2003/2004)
=(2005/2)*(1/2004)
=2005/4008