Find the domain and range of the function.
-$$f ( x ) = - 5 x ^ { 2 } - 80 x - 324$$
A) Domain: $( - \infty , - 4 ] ;$ Range: $[ 0 , \infty )$
B) Domain: $( - \infty , \infty )$; Range: $( - \infty , 8 ]$
C) Domain: $( - \infty , \infty )$; Range: $( - \infty , - 4 ]$
D) Domain: $( - \infty , - 4 ]$; Range: $[ 8 , \infty )$

Question

Quizplus · Accepted Answer

The domain of a quadratic function is all real numbers $(- \infty, \infty)$. The range is determined by the vertex of the parabola, which opens downwards, so the range is $(-\infty, -4]$.

Find the Domain and Range of the Function f(x)=−5x2−80x−324f ( x ) = - 5 x ^ { 2 } - 80 x - 324f(x)=−5x2−80x−324

Find the Domain and Range of the Function $f ( x ) = - 5 x ^ { 2 } - 80 x - 324$