jard, 6 months ago There is also the approach of representing 0.999… as the infinite geometric series 9(1/10) + 9(1/100) + 9(1/1000) + 9(1/10000)… which, by definition, is equal to 9(1/10) / (1 - 1/10) = 0.9 / 0.9 = 1.
There is also the approach of representing 0.999… as the infinite geometric series 9(1/10) + 9(1/100) + 9(1/1000) + 9(1/10000)… which, by definition, is equal to 9(1/10) / (1 - 1/10) = 0.9 / 0.9 = 1.