Question

domain:
(the image shows a number line from -5 to 5 with a blue line segment between -3 (closed dot) and 3 (closed dot))

Explanation:

Step1: Identify interval endpoints

Closed dots at $x=-3$ and $x=3$ mean these values are included.

Step2: Define the domain interval

The line connects $-3$ to $3$, so all values between them are included.

Answer:

$-3 \leq x \leq 3$ (or in interval notation: $[-3, 3]$)