Which are true of the function f(x) = 49(1/7)^x? Check all that apply.

1. The domain is the set of all real numbers.
2.The range is the set of all real numbers.
3.The domain is x > 0.
4.The range is y > 0.
4.As x increases by 1, each y-value is one-seventh of the previous y-value.
5.The initial value for the function is 7.