Answer:
Yes, it is a function.
The domain is (∞,∞) and the range is (∞,5].
Step-by-step explanation:
A function needs to pass the vertical line test: It can only have one x value and one y value at a time. You simply hold a ruler to your screen and drag it from left to right (or vice versa) and see if the function touches the ruler once. If it touches once at any given point, it's a function!
The domain is (∞,∞) because there is a line on both ends- meaning it stretches infinitely. The range is (∞,5] since it goes down infinitely and stops at y = 5.
