Describe the graph of f(x) by selecting the correct statement about the average rat...

Check the final answer first, then review the worked steps.

Problem

Describe the graph of f(x) by selecting the correct statement about the average rate of change on given intervals.

Answer

The average rate of change is negative on the interval [1, 3] and also on the interval [6, 7].

Step-by-step solution

1. Calculate the average rate of change on interval [1, 3]: The average rate of change of a function $f(x)$ on an interval $[a, b]$ is given by the formula $\frac{f(b) - f(a)}{b - a}$. From the graph, we can identify the points $(1, 1)$ and $(3, 0)$. Therefore, the average rate of change on $[1, 3]$ is $\frac{0 - 1}{3 - 1} = \frac{-1}{2}$. Since the value is negative, the average rate of change is negative on this interval.
2. Calculate the average rate of change on interval [6, 7]: Using the same formula, we identify the points $(6, 2)$ and $(7, 0)$. The average rate of change on $[6, 7]$ is $\frac{0 - 2}{7 - 6} = \frac{-2}{1} = -2$. Since the value is negative, the average rate of change is negative on this interval.
3. Evaluate other intervals for comparison:
- Interval [0, 1]: Points are $(0, -1)$ and $(1, 1)$. Average rate of change = $\frac{1 - (-1)}{1 - 0} = \frac{2}{1} = 2$ (positive).
- Interval [3, 4]: Points are $(3, 0)$ and $(4, 1)$. Average rate of change = $\frac{1 - 0}{4 - 3} = \frac{1}{1} = 1$ (positive).
- Interval [0, 1] and [3, 4]: As calculated above, the average rate of change is positive on both these intervals.
4. Determine the correct statement: Based on the calculations, the average rate of change is negative on the interval [1, 3] and also on the interval [6, 7]. This matches the first option.