The domain of a function is the set of inputs, that is, all the x-values for which the function is defined. Here in this problem, you haven't provided any function, so I couldn't give you an exact answer. However, suppose your function is the following:
The domain of this function can be found as:
This is so because the logarithmic function is not defined when its argument is less than or equal to 0. Therefore, using interval notation we have that the domain is: