domain and range of g(t)= √(16+7^-t)

Question

I know a square root cannot be negative so 

16+7^-t >=0

7^-t>=-16

 

since an exponential function cannot be negative, can i assume that t is all real numbers?

how do i find the range?

Answer 1

Correct. Since 7^-t > 0, the domain is R

Since 16 + 7^-t > 16, g(t) > 4, the range is (4, ∞)