Chapter 6.2, Problem 7SBE

Sign of the Derivative: Suppose $f=f\left(x\right)$. What is the sign of $\frac{df}{dx}$ in each of the following situations?

a. The function $f$ is increasing.

b. The graph of $f$ has reached a peak.

c. The function $f$ is decreasing.

d The graph of $f$ is a horizontal line.