1. The x-intercepts are x = 0 and x = 6. You can find these by looking for where the line crosses the x-axis. You can see here that it does so at 0 and 6.
2. The maximum value for this function is looking for the f(x) value at the highest point. In this case, you will see that f(x) at the highest point is 120. This happens at x = 3. Once again, this can be found just by looking for the highest point on the graph.
3. Since that is the absolute highest point, it is also the point where is goes from increasing to decreasing. As a result, we know the increasing interval is x<120 and the decreasing interval is x > 120.
4. Finally, the average rate of change between 3 and 5 is -30. You can find this by determining the amount of change in f(x) and dividing it by the amount of change in x. The basic formula is below.
-30