Answer:
All real numbers
The problem:
What is the domain of f(x)=|x-1|?
Explanation:
There are no restrictions when plugging into an absolute value function.
That is |u|=a number always for any value of u.
The domain for f(x)=|x-1| is therefore all real numbers. There is no number that you can think of that wouldn't have a distance from 0.