Question

PLEASE HELP (:

The range of the function

f(x) = x + 5 is {7, 9}. What is the function’s domain?

A. {2, 4} B. {-2, -4} C. {12, 14} D. {-12, -14} E. {0, 5}

Answer 1

{12,15}

Explanation:

Given the function f(x) = x+5, if the range of the function is {7,9}, the domain of the function is derived by simply finding the value of the function at each end point.

At endpoint x = 7,

f(7) = 7+5

f(7) = 12

At endpoint x = 9

f(9) = 9+5

f(9) = 14.

The function domain is therefore at {12,14}