(1-1/4)(1-1/9)(1-1/16).(1-1/10000)原题.(1-1/2^2)(1-1/3^2)(1-4^2)…(1-1/100^2)
问题描述:
(1-1/4)(1-1/9)(1-1/16).(1-1/10000)
原题.(1-1/2^2)(1-1/3^2)(1-4^2)…(1-1/100^2)
答
(1-1/4)(1-1/9)(1-1/16).......(1-1/10000) =(1-1/2^2)(1-1/3^2)......(1-1/100^2) =(1-1/2)(1+1/2)(1-1/3)(1+1/3).....(1-1/100)(1+1/100) =1/2*3/2*2/3*4/3.....99/100*101/100 =101/2
答
(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)……(1-1/100)(1+1/100)
=(1/2)*(3/2)*(2/3)*(4/3)*(3/4)……*(101/100)=0.505
答
101/200
同学你拆什么 原题就可以转化为
(1-1/2)(1+1/2)(1-1/3)(1+1/3)……(1-1/100)(1+1/100)