Which of the following graphs is a function?

An easy way to tell whether a graph is a function or not is to employ the verical line test. If you see any two y values that correspond to one x value, that means it is not a graph of a function, but rather a relation. In a we see that if we were to scan a vertical line from the left to right, there would be a point where an x value corresponds to two y values, which is at 2 to the left from the origin. In graph c you can find an x value that correspons to more than one y value at the origin, the same with graph b. With graph d, though, we see that all x values corresponds to only one y value so that graph is the one that is a function.

3/6   and 9/18

step-by-step explanation: