State the domain and range of the function.
-$$f ( x ) = - 2 ^ { x } - 5$$
A) domain: $( - \infty , \infty )$; range: $( - \infty , - 5 )$
B) domain: $( - \infty , \infty )$; range: $( - \infty , - 5 ]$
C) domain: $[ 0 , \infty )$; range: $( - \infty , \infty )$
D) domain: $( - \infty , 0 ) \cup ( 0 , \infty )$; range: $( - \infty , - 5 )$

Question

Quizplus · Accepted Answer

The domain of an exponential function is all real numbers $( - \infty , \infty )$, because you can input any real number into the function. The range is $( - \infty , - 5 )$ because as $x$ increases, $-2^x$ decreases and approaches $-\infty$, and as $x$ decreases, $-2^x$ approaches $-5$ but never reaches it, due to the subtraction of 5.

State the Domain and Range of the Function f(x)=−2x−5f ( x ) = - 2 ^ { x } - 5f(x)=−2x−5

State the Domain and Range of the Function $f ( x ) = - 2 ^ { x } - 5$