Answer
See graph (red).
domain $(-\infty,\infty)$, range $[-1,\infty)$.
Work Step by Step
Step 1. To obtain the graph of $f(x)=x^2-1$ from $y=x^2$, shift the curve 1 unit down. See graph (red).
Step 2. We can find the domain $(-\infty,\infty)$ and the range $[-1,\infty)$.
