Answer:
Domain: x <= 4
Range: all real numbers
Explanation:
The domain is all the x's in the graph. If you have an equation, its it's all the x's that are allowed to go into the equation. See on the image that there is no graph if you are standing at x=5 or x=6 or anywhere farther to the right. It exists at 4 and everywhere forever if you keep walking on the x-axis to the left. So the domain is x<=4 written in set notation. In interval notation it is written (infinity symbol, 4].
Range is all the y's on the graph or any y output that could be created by the equation. If you are walking up and down on the y-axis and look for the graph, you could walk forever up the y-axis or down the y-axis and still be able to see the graph. So the range is all real numbers. Range is (-inf, inf) in interval notation.