Question

The graph below shows three functions: Graph of function f of x equals 2 to the power of negative x. Graph of function g of x equals 5 to the power of x. Graph of p of x is a line segment connecting points negative 1, negative 3 and 2, 12. Which function has all real numbers as its domain?

Answer 1

The straight line is a polynomial. ALL polynomials have real numbers as its domain.

The exponential functions f(x) and g(x) both have the form b^x or b^(-x). Both these exponential functions have a real domain, but the range of both are limited to strictly positive numbers.