The Domain is the set of all x-values that satisfy the equation, or in other words, how far left or right the equation points. The Range is the set of all y-values that satisfy the equation depending on the domain values, and the range is how far up or down the function points.
Looking at the graph, the domain is:
[3, ♾️)
This is the case because the graph begins at 3, hence it is a defined starting point, and so brackets are used to indicate this.
Looking at the graph, the range is:
(-♾️, ♾️)
This is the case because the graph rises towards infinity as the x-coordinates become greater than 3. At the x-coordinate x=3, the graph extends infinitely downwards, and thus the graph extends upwards and downwards towards positive and negative infinity. Also note that infinity is a concept, not a defined point, so we use parentheses to indicate this.