Is the function in the graph non-linear?

Question

On a coordinate plane, a line curves down.
Yes, because it has a constant rate of change.
Yes, because it does not have a constant rate of change.
No, because it has a constant rate of change.
No, because it does not have a constant rate of change.

Answer 1

The answer is: Yes, because it does not have a constant rate of change.

A non-linear function does not have a constant rate of change, which means that as you move along the graph, the slope of the curve changes. Since you described a graph with a line that curves down, it indicates that the rate of change is not constant, confirming that the function is non-linear.