Question

Which statement best describes the domain and range of f(x) = –(7)x and g(x) = 7x?
f(x) and g(x) have the same domain and the same range.
f(x) and g(x) have the same domain but different ranges.
f(x) and g(x) have different domains but the same range.
f(x) and g(x) have different domains and different ranges.

Answer 1

Same domain but different ranges.

Reason: Both functions are defined for all real x, so domain = (−∞, ∞). If g(x) = 7^x then g(x) > 0 so range = (0, ∞). If f(x) = −7^x then f(x) < 0 so range = (−∞, 0).