Chapter 3 - Derivatives - 3.6 Derivatives as Rates of Change - 3.6 Exercises - Page 180: 2

If $\frac{dy}{dx}$ is large then small change in $x$ will result in relatively large change in the value of $y$.

If $\frac{dy}{dx}$ is large then small change in $x$ will result in relatively large change in the value of $y$, because the average change in $x$ will effect the value of $y$.