How do you do this? I'll give brainliest, please help.

Answer:
Domain is all values of X or (-∞,∞)
Range is all the possible values of Y. Since it goes up to 3, and then it goes down, it's all values less than or equal to y, or (-∞,3] or y ≤ 3 (depending on how you need to enter the response.
Step-by-step explanation: