Answer:
All Real Numbers
Explanation:
The Domain for a function simply is all the possible x values.
When graphing this function, you'll realize that it's continuous and passes all x values.
Additionally, when looking at it, you'll realize you can input any number of your choosing.
When trying to evaluate the domain of other functions, you can look at if any values of x will create an undefined value.
For example, some functions may have x in the denominator, and since the denominator can not be 0, there will be a discontinuity.
Other examples where the domain wouldn't be all real numbers would be if x was under a square root and couldn't be negative, or if the function was a vertical line.
Hope that helps, please let me know if you have any queries.