Answer
See graph, domain $\{x|x\ne\frac{k\pi}{2} \}$ (where $k$ is an odd integer), range $(-\infty,-4]U[4,\infty)$.
Work Step by Step
Step 1. See graph for $y=-4sec(x)$.
Step 2. Based on the graph, we can determine the domain $\{x|x\ne\frac{k\pi}{2} \}$ (where $k$ is an odd integer), range $(-\infty,-4]U[4,\infty)$.