Answer
See below.
Work Step by Step
Step 1. To obtain the graph of $f(x)=1-2^{x+3}$ from $y=2^{x}$, shift the curve 3 units to the right, reflect across the x-axis, then shift 1 unit up. See graph.
Step 2. We can determine the domain is $(-\infty,\infty)$; the range is $(-\infty,1)$; and the horizontal asymptote $y=1$.
