Answer
Domain: All real numbers.
Range: $(-\infty , -8]$
Work Step by Step
Given $$ h(d) = -0.4(d+15)^2 -8.$$ The parabola opens downward as we can see from the graph. Its vertex gives the maximum point. The domain and range are given by:
Domain: All real numbers.
Range: $(-\infty , -8]$.
