You must find the domain and range to see if it's a function

1.) To start, for the domain and range of the function, look at the direction the graph is going on both ends, and up and down. Since it appears to be that the graph is increasing along both the y and x axis forever, the domain would be from (-∞, ∞) since it is forever increasing on both ends, and for the range, it would be [-1, ∞) since it starts at -1 and includes it, while going on forever to ∞, which would not be included since as the graph goes up, it is getting closer and closer to ∞, however it never actually reaches it. According to the vertical line test, this graph would be a function (the vertical line test is when you draw vertical lines on the graph to see if any part of the graph has the same x value. If it has the same x-value, it is not a function.)

2.) According to the things said above, the domain would be from (-∞, ∞), however, the range is slightly different since this graph looks like two functions on one plane. Because the graph jumps, rather than being one connected graph, your range would be (-∞, -1] U [1,∞). The U stands for union which connects the two ranges. This graph, unlike the first one, would not be a function, since if you were to draw a vertical line through it, there would be points that are on the same line, which means there are x-values that have more than one y-value, making it not a function.