Sqrt(2)/2 can not be written as a decimal number. A decimal number is a rational...

zorgmonkey · on May 2, 2023

No, any rational number with a denominator that has only the prime factors of 2 and 5 will have a finite and exact decimal representation in base 10.

jameshart · on May 2, 2023

That's exactly the same thing as I said, using different words.

And anyway, is Sqrt(2)/2 such a number?

davrosthedalek · on May 3, 2023

That's not quite what you have said. 3/2 does not have an integer power of 10 as the denominator, but can be written as a decimal. Of course, it can also be written as a fraction with a integer power, for example 15/10. (You are of course right on the 1/sqrt(2) issue)