Question

The graph of a quadratic function with vertex (2, 0) is shown in the figure below.

Find the range and the domain.
Write the range and domain using Interval notation.

Answer 1

Domain: (-∞, +∞)

Range: [2, +∞)

Explanation:

Domain is the "allowable x-values/inputs"

Range is the "possible y-values/outputs when the x-values in the domain are inputted".

From the graph, notice how each end of it extends infinitely to the left and to the right. This means that the domain is infinite and there are no restrictions. Writing it in interval location would look like this:

(-∞, +∞)

Also, notice how the y-values increase from the vertex but do not go below it. That suggests that the range is "lower-bounded" to the vertex, and increases infinitely. Writing it in interval location would look like this:

[2, +∞)