Question

Best estimate for domain and range

Answer 1

Answer: The domain is
`-\infty < x < \infty` (or
`(-\infty,\infty)` in interval notation). The range is
`y\geq 3` (or
`[3,\infty)` in interval notation).

Explanation:

The domain is
`-\infty < x < \infty` because quadratic functions always extend forever in either direction along the x-axis. You do not include infinity because these values are not actually numbers.

The range is
`y\geq 3` because the y-value of the vertex as shown in the graph is 3, and the graph is a positive graph. You include the 3 because when x=0, y=3.