题目

0.9*0.9*0.9*0.9*0.9*0.9*0.9*0.9*0.9*0.9*循环0.9等于?
0.1*0.1*0.1*0.1*0.1*0.1*0.1*0.1*0.1*0.1*循环0.1等于?

提问时间：2021-04-29

答案

> >0.999999.= 0.9+0.09+0.009+0.0009...>=0.9 + 0.9/10 +0.9/100+0.9/1000.>=0.9 + 0.9/10 +0.9/10^2+0.9/10^3+0.9/10^4.>=0.9(1+ (1/10) + (1/10)^2 +(1/10)^3 + (1/10)^4 +...+(1/10)^n) > >1+x+x^2+x^3+.+x^n+....