## Practice Problems

Work through the odd-numbered problems 1-29. Once you have completed the problem set, check your answers.

### Problems

In problems 1 and 3, sketch the graph of the derivative of each function.

1. Use Fig. 20.

**Fig. 20**

3. Use Fig. 22.

**Fig. 22**

In problem 5, the graph of the height of a helicopter is shown. Sketch the graph of the upward velocity of the helicopter.

5. Use Fig. 24,

**Fig. 24**

7. In Fig. 26, match the graphs of the functions with those of their derivatives.

**Fig. 26**

9. Use the Second Shape Theorem to show that is monotonic increasing on .

11. A student is working with a complicated function and has shown that the derivative of is always positive. A minute later the student also claims that when and when .
Without checking the student's work, how can you be certain that it contains an error?

13. Fig. 29 shows the graph of the **derivative** of a continuous function $\mathrm{g}$.

(a) List the critical numbers of .

(b) For what values of does have a local maximum?

(c) For what values
of does have a local minimum?

**Fig. 29**

In problem 15, the graph of the upward velocities of several helicopters are shown. Use each graph to determine when each helicopter was at a relatively maximum and minimum height.

15. Use Fig. 31.

**Fig. 31**

In problems 17-21, use information from the derivative of each function to help you graph the function. Find all local maximums and minimums of each function.

23. so . Without graphing the function, you can be certain that has how many positive roots? (zero, one, two, more than two)

25. has a root at . Without graphing , show that has no other roots.

27. Each of the following statements is false. Give (or sketch) a counterexample for each statement.

(a) If is increasing on an interval I, then for all in .

(b)
If is increasing and differentiable on , then for all in .

(c) If cars and always have the same speed, then they will always be the
same distance apart.

29. (a) Give the equations of several different functions which all have the same derivative .

(b) Give the equation of the function with derivative which also satisfies .

(c) Give
the equation of the function with , and the graph of goes through .

Source: Dale Hoffman, https://s3.amazonaws.com/saylordotorg-resources/wwwresources/site/wp-content/uploads/2012/12/MA005-4.3-First-Derivative.pdf

This work is licensed under a Creative Commons Attribution 3.0 License.