Question

how to proof 1=0.999 in mathematics ​

Answer 1

Answer:

The Archimedean property: any point x before the finish line lies between two of the points (inclusive).

There is an elementary proof of the equation 0.999... ...

More precisely, the distance from 0.9 to 1 is 0.1 = 1/10, the distance from 0.99 to 1 is 0.01 = 1/102, and so on.