What are the domain and range of f (x) = 2 (3^x) ?

domain: (-infinity, infinity); range: (0, infinity)

domain: (-infinity, infinity); range: (2, infinity)

domain: (0, infinity); range: (-infinity, infinity)

domain: (2, infinity); range: (-infinity, infinity)

Okay so the domain in this example is - infinity to infinity because 3^x is never an illegal expression where x is any number. As you decrease the value of the domain, 3^x approaches 0, we can assume that it eventually reaches 0, since 2 multiplied by 0 is still 0, the range must be (0, infinity).

Therefore, the answer is the first one.