The answer for the question shown above is the second one, which is: The domain is all real numbers. The range is all real numbers greater than zero.
The explanation is shown below:
You have the following function given in the problem above f(x)= (1/5)^x. As you can see, it is a exponential function. By definition, the domain of the exponential functions is all the real numbers anf their range is all real numbers greater that zero.
