Help with infinities..

Question

Which of the following functions have a domain of (-∞, ∞) and a range of (-2, ∞)?

Check all that apply.
F(x)=3^x+2
F(x)=3^x-2
F(x)=0.25^x+2
F(x)=0.25^x-2

Answer 1

The Domain is the set of values for "x" that can be used in the function. For all four functions x may be any real number, i.e., (-∞, ∞).

 

n^x > 0, therefore the second and fourth functions have a range of (-2, ∞).