Answer:
Domain of the function is Option 1. (-∞,1)∪(1,∞).
Explanation:
In the question two functions have been given as
f(x) = (x-1)/2x and g(x) = (x-1)/x
Now we have to find a function defined as (f Ф g(x))
We put the value of g(x) in f(x) to find a new function defined as fФ(g(x))
⇒ fФ(g(x)) =

Now we multiply numerator and denominator by x.
fФ(g(x) =

=

The function is defined only if (x-1)>0 ⇒ x >1
and (x-1)<0 ⇒ x <1
So the domain will be the combined set of ( 1,∞) and (-∞,1) or (1,∞)∪(-∞,1).