Final answer:
To find the correct function for a graph, identify the slope and y-intercept for linear functions, or determine if the graph doesn't match typical function behavior and thus 'd' may be the answer.
Step-by-step explanation:
To determine which function is represented by a graph without seeing the specific graph, I can explain how to analyze the characteristics of each function and match them to the graph's visual properties.
Functions a and b represent straight lines where the number in front of x (the coefficient) indicates the slope and the constant term indicates the y-intercept. Function c has a positive slope and a positive y-intercept, making the line go upwards as x increases.
Function d suggests that the graph does not represent a function which might indicate either a vertical line or something that fails the vertical line test.